If there are three persons in One God, what is a 'person', and how is the Holy Spirit a person?

We don't really know, because we don't know God – we only know THAT he is, and what he has revealed about himself to us. It is a bit like physics, where the scientist has certain data about energy and particles, and has to make sense of it by developing new words and theories. Light, for example, is both a wave and a particle, and space is curved: these things don't seem obvious to us, but the scientists have concluded that they must be true in order to make sense of the phenomena.

The early Christians had evidence that Jesus was God, and they knew that his Father in heaven was God, and that the Holy Spirit was also God, but from the way that Jesus spoke about them and about his relationship with them it was clear that although each of these three was God, they were each distinct from the other two.

God did not do the theology for us: he left us to work it out. So in the first few centuries the Christians reflected on all of this and eventually chose the word 'person' (from the Latin word for a dramatic role or an actor's mask in a play) to describe these relations within God.

What is confusing is that these days we use the word 'person' to refer to a human person, who is inevitably an individual, because human nature is divided up between all the people in the world. In God's case, a divine Person is not an individual in the same way, because God's nature is not 'divided up' between the Persons: that would make each Person only partially God, or else one God among three Gods – which would not make sense.

How is Mary the mother of God and not just the mother of Jesus? Is she the mother of the Blessed Trinity?

She is the 'Mother of God' because she is the Mother not just of the human nature of her Son but of his Person, and that Person is divine. So she was (is) the Mother of God because she is the Mother of the Son, not the Mother of the Trinity.

It is important to remember that being a Mother is not just a biological fact, but a personal relationship. Also, the whole point about the Incarnation is that the divine and human natures of Jesus were completely united in his Person (that is to say, in 'who he is'). You can't just separate them again when you start to talk about Mary.

If Our Lady was without Original Sin, therefore perfect, in what way is her perfection different from God's?

She was perfect as a creature (that is, as made by God), whereas God is perfection itself. She is limited by her nature as a human being, whereas God is unlimited, infinite.

If Confirmation is a declaration of faith, isn't it just like a second Baptism?

Baptism is much more than a declaration of faith, and so is Confirmation, actually. Baptism involves a process of rebirth, which is a real, interior process and therefore hidden, but it is made visible to some extent by the form of the ritual that brings it about. In Baptism the Spirit of God enters our souls in a new way. Of course, God as Creator and Sustainer of everything is always within everybody as the cause of our existence. But in Baptism there is a new connection established, which builds on the old one. A new life begins, a life that we say is 'in Christ' because the Holy Spirit that enters into us makes our life into a part or extension of his.

As for Confirmation, the theology of this sacrament is still being worked out, but it seems to involve an 'unsealing' or a releasing of some of the powers placed in us at our Baptism, particularly the power of bearing witness to our faith. The Holy Spirit is invoked upon us by the Bishop, and That which was already deep within us comes 'down' on our heads (symbolically speaking) like a kind of invisible flame, to rekindle that new life in a way that becomes a more visible service to the whole Church.

How old are people when they are confirmed, usually? Should we not be confirmed before we make our first Holy Communion?

These days in England the age is usually around 12 to 14, but it varies. There is no particular reason why we should receive it before Holy Communion (which is normally around 7 or 8). It is not a stage on the way to Communion, after all. We are members of the Body of Christ before we are confirmed – Confirmation only strengthens us for witnessing to those outside the Church.

On the other hand, there are mysteries here that we don't fully understand, and the mentality that denies that and tries to make everything simple is extremely dangerous. The sacraments are not just sociological and psychological ways of affirming our membership in a community, our maturity, or whatever. What if to be able to receive communion properly one needs the fortification of confirmation? The Holy Spirit has to help us receive communion, and maybe without having first received the sacrament of confirmation we do not have the 'space' in our soul to receive what God wants to give us. What if confirmation does something to us that we need done before we receive communion? Then to postpone confirmation until after First Communion would be to pretend that anyone can receive communion just by opening their mouth.

It might be worth mentioning that while the Sacraments themselves go back to Christ, the exact timing and arrangements for them, as well as many of the details of the ritual, have developed over time. In fact they have developed differently in the Eastern Orthodox Church, where Confirmation (Chrismation) usually goes together with Baptism, and Communion is given much earlier than in the Catholic Church.

On the first Pentecost, God directly performed the Confirmation. Why do we need a bishop or a priest to confirm us today?

Just as God himself performed the first Ordination (at the Last Supper), and the men he ordained to the priesthood went on to ordain others, so (this time from heaven) he 'confirmed' the Christian community at Pentecost in order to send them out into the world, and the Sacrament is transmitted down through time by the successors of the Apostles. The Sacraments are all divine actions, but they are entrusted to the Church. That is what the Church is.

Can a really good non-baptised person go straight to heaven?

Maybe. That's up to God's judgment. He may count the person as having been baptized 'invisibly' by an act of repentance for sin and a desire for union with God. What we do know, however, is that visible Baptism implants the divine life within us, and opens up a new and eternal destiny that is greater than anything we could have a right to hope for without it. So we should do what we can to bring others to long for this Sacrament, for the sake of their salvation. It may not be the only way God can bring them to himself, but it is the only way we know about.

When Catholics pray for Christian unity, aren't they really just asking the other churches to join the Catholic Church?

In a way, because as Catholics we believe that the fullness of the Church subsists in the Catholic Church (Catechism, 816-19), but we are also repenting of our own sins, sins that have made that conversion seemingly impossible for so many. If we were all saints, others might not have such good reasons not to recognize the Church for what she really is. It is also worth reflecting that the Church herself grows with each new member – we are not asking people to cram themselves into a box, but to join a people. In other words, the Church turns towards them, and can expand to accommodate them. The more people join, the more room there is, and the more diversity within an underlying unity that is given by God.

Does the Eucharist really turn into the 'body and blood' of Jesus Christ when the priest says the words of consecration? Is this just symbolic? Presumably the bread and wine used in the Mass don't look any different under a microscope.

The Catholic Church teaches that the bread and wine used in the Catholic Mass does really change – and not just symbolically – when it is consecrated in the right way by an ordained priest (see Catechism paras 1322-1419, and especially on this point paras 1374-7). This change does not show up in microscopes, and it is no way accessible to the physical senses. A priest who is allergic to gluten will still be allergic to the Host after it is consecrated. The problem that modern people have with this is that they think a thing IS only what can be seen and touched. We grow up thinking the 'substance' of anything is its physical composition – so the substance of a pot is clay, or the substance of a ring is the gold it is made of. What the Church is telling us is that the underlying substance of a thing is distinct from its 'appearances'. But the Church does NOT explain what that deeper substance is and how it is related to the appearances. That would be philosophy, or metaphysics, and the Church leaves it to philosophers to argue and worry about. What the Church tells us is simply the result that we need to know: that Jesus Christ, in his risen, resurrected body which lives now in heaven, is truly present in the Blessed Sacrament.

I feel it is a disgusting idea that we are really eating the body of Jesus. Why should we have to do that?

The Jews thought it was a disgusting idea, too, when Jesus first told them about it (read Chapter 6 of the Gospel of John). They wanted it to be just a metaphor but Jesus made very clear that he meant it literally. But think about why it feels disgusting to you. Eating a human body IS disgusting – it is in fact an evil thing to do – because we destroy and divide the body with our teeth in order to swallow it, and because eating implies killing. But in the case of the Eucharist, Jesus is not able to die or suffer or be divided in any way. It is his risen, invulnerable body we are eating. Furthermore the whole Jesus is present in every particle of what looks like bread, so when we chomp up the Host we are not even dividing his body.

As for why he wants us to do this, the reason is "so that we will have life in us" (John again). So he wants to replace our physical life that is nourished by such things as bread by a supernatural life that comes directly from him. He wants to come as close to us as he possibly can, in every way that he can, including physically inside us, so that we can pray to him with our bodies and feelings and not just our thoughts and ideas. He wants to make us part of him by making himself part of us, and that desire is expressed most perfectly in Holy Communion.

Our Lord said 'Leave everything and follow me'. Most Catholics lead ordinary lives with homes and possessions, etc. Are they lost?

Our Lord certainly called the Apostles to leave their previous lives behind – although even there we hear later in the Gospels about the visit to Peter's mother-in-law, which suggests not only that he was married, but that the disciples did not have to cut themselves off from their families entirely. Not every follower of our Lord was asked for that radical a commitment, though. When he told the rich young man to sell all his possessions and give the money to the poor, that has normally been interpreted as a 'counsel of perfection', which is directed at those who have a special calling to what later came to be called 'the religious life'.

The same pattern repeated itself in St Francis's time. He also called for his followers to make a radical break from their earlier life, but when married people approached him, especially if they had dependents, he asked them instead to live the spirit of his teachings within their own state of life, as best they could. That was the origin of the so-called 'third order' or 'secular Franciscans'.

The early Christians sold their possessions and lived in communities. This seems to be impracticable to us today. How did they manage it?

It may not be as impossible as you imagine. Every so often that way of life is rediscovered by a group of people, inside or outside the Church. The early hermits and monks did it, and so did the Benedictines, and later the Franciscans. It is no more impractical today than it was then. Usually possessions are not done away with altogether, but held in common, so that it is the community that owns and manages them, rather than the individual.

In fact, the Church still teaches that the 'consecrated life' of complete dedication to God – usually associated with poverty, chastity, obedience, whether as a hermit or in community – is an essential element in the Church. It cannot be imposed on everyone, but many are called to commit themselves in this way, and thus to contribute to the holiness of the Church (Catechism, 914-33).

Can the Catholic Church teach things that are wrong?

It is important to make a distinction between what the Church does and teaches as a whole and in her own 'person', as it were, and what individuals (even very highly placed individuals) do in her name. Not everything the Pope does, for example, is an action of the Church. When he goes swimming, or chats with his friends, that is not the Church swimming or chatting. There have been Popes who made mistakes in their theology. The Pope is only acting in the person of the Church in his most solemn teaching, when he uses his authority to bind the consciences of the faithful. In those circumstances, God must protect him from error, if he is not to allow his people to be gravely deceived in a matter that concerns their salvation. Similarly, the teaching of an Ecumenical Council, when all the Bishops are gathered together, reflects the mind of the Church.

Many older people have claimed that their Catholic schools taught them things in the name of the Church that turned out later to be false or misleading: that non-baptized pagans will go to hell, for example, or that wives must always try to have as many children as physically possible. If so, this merely illustrates the difference between authoritative teaching and teaching which isn't authoritative, but pretends to be.

Doesn't the Church sometimes change its mind? For example we do not hear about 'limbo' any more. What about purgatory?

The Church has never changed her mind about the essentials of the faith, as a closer study of history will show. She does sometimes play down one thing and play up another, depending on the circumstances, and also certain doctrines do develop over time. Even the doctrine of the Trinity took a while for the early Church to work out, think through and then state in a Creed. That doesn't mean that the Church 'invented' the Trinity, or 'changed its mind' about God. But it took time to think through all that Jesus had said and done, and to work out the implications of it – with the help of the Holy Spirit. The early Apostles were fishermen and tax collectors, not theologians! (In John 16:13 it is clear that Jesus intends this to happen, and he even implies it will be a gradual process: 'When the Spirit of truth comes, he will guide you into all the truth'.)

Purgatory is one of those teachings that went out of fashion for a while in some places, but the Church has always taught it and still does (see Catechism, 1030-32). 'Limbo', meaning a place where the children go who have died before committing any sins but who, being unbaptized, cannot attain to heaven, was only ever a theological opinion, not a dogmatic teaching of the Church, and these days most theologians would argue against it (because they have a more developed understanding of how God's grace can reach people if the sacraments are not available). Sometimes theologians still talk about 'the Limbo of the Fathers', meaning the place – more a place of waiting than of punishment or even of purification – where the patriarchs and prophets of the Old Testament right back to Adam and Eve must have been kept after death, until the Passion of Our Lord opened for them the gates of Heaven. Some have speculated that this 'Limbo' would have included also good pagans such as Socrates and Confucius. But all of this is also just a speculation.

Many people today cannot take the Church seriously because of all the bad things it has done throughout history (Inquisition, Crusades, etc.). As a Catholic do I have to justify these things? Can I explain them?

It is true that members of the Church – even Bishops and Popes – have done many terrible things at various points in history. It would be strange if they had not, since Baptism and even Ordination or election to the papacy does not destroy free will. All Catholics remain free to do evil, and many have chosen to do so, despite the grace that is available to them in the sacraments of the Church.

Not all the evil deeds that we hear about were quite as evil as people suggest, however. Don't believe all that you hear or read without checking it first! Also, many of these things are more understandable (though not necessarily excusable!) if one takes into account the social and historical context. The Crusades, for example, were in part a war of defence against a perceived threat, and an answer to the eastern Patriarch's plea to the West for help. The Inquisition was an attempt to defend the Christian people against heretics who were viewed at the time a bit like terrorists are today: criminals attacking innocent people and undermining the fabric of civilized life. The worst and cruellest Inquisition was not the Roman one but the Spanish, which was run by the State, not the Church.

Many of the things we recognize today as abuses came about through a too-close identification between the Church and the State – but it was a connection that seemed natural and unavoidable in those times, and we only see things differently now because enough time and thought has gone on for certain lessons to be learned.

We do not have to justify all these things. If historians and social scientists help us to explain them, and understand how they came about, that is all to the good. But we need to remember, sometimes, that equally bad or worse things have been done outside the Church (by Stalin, Pol Pot and a whole host of tyrants). It is not being a Catholic that leads to these things being done: it is being human, being weak, or coming under the influence of evil. Against evil our surest defence is prayer, the sacraments, and the teaching of the Church.

For more on the Inquisition, click here

The Pope is supposed to be infallible. Can there be bad popes?

Certainly – and there have been (see answer to question above). To be infallible is to be incapable of failing – in this case, of failing to preserve the 'deposit of faith'. It is not the same as being 'impeccable' or sinless, as several wicked Popes have unfortunately demonstrated. (See Catechism, paras 889-91).

How can we take the Church seriously when it persecutes heretics, and even burns people alive, or when priests (even popes sometimes) commit the most appalling crimes against humanity?

The Church – meaning that body of people who claim to be followers of Christ, and who receive the sacraments – is not sinless and doesn't claim to be. In fact it is a Church of sinners. What it does claim is to have preserved true teachings (even if it doesn't always live up to them) and valid sacraments that convey divine grace – for example the grace of forgiveness in the sacrament of Confession, that makes it possible to leave those sins behind and regain one's innocence (even if many people then go back and sin again). Those claims alone are worth taking seriously. The thing to do is to look not at the sinners, who would be there even if the Church wasn't, but at the saints, who wouldn't be there without the access to grace that others squander.

No one today is going to defend the burning of heretics. It took a long time for the Church to realize that this kind of behaviour is unacceptable, because that kind of cruelty was endemic and normal in the cultures of the time (like slavery). Heretics were regarded like terrorists are today – as the enemy of the free society – and were treated accordingly with the maximum punishment, partly to deter others. Even today the 'civilized' countries permit the use of torture and lying by their secret service agents to obtain information deemed vital to national security. In the Middle Ages, Catholic and non-Catholic countries did the same thing, but in point of fact the Church modified and softened the common practice – so that, for example, the Roman Inquisition was a relatively more civilized affair than the Spanish one, which was run by the State.

What are 'indulgences'?

Indulgences are best understood in the context of the Church's teaching about forgiveness (Catechism, 1471-9). Every sin has two kinds of consequence: it damages our relationship with God, and it damages ourselves. (It also may have effects on our relationship with other people and the rest of creation.) The first kind of damage can be put right instantly by repentance and absolution (forgiveness); the second takes more time to heal. In order to help the healing process, which is called purification, the Church, through the priest in the sacrament of Reconciliation, can impose a 'penance' or good work to be done. (It might be a prayer, for example.) This compensates in some measure for the damage that that sin has done, or helps to wash it away. Earthly suffering in general can be regarded in a positive light as a way of loosening the grip of sin and undoing its effects: if I die before completely achieving this then I can carry on in Purgatory.

The point about indulgences is that one person can do much more than make up for their own sins. They can 'offer' their own good works for the sake of others, and because we are all bound together in one body by the Spirit of love, this 'offer' is be accepted. Thus one person can help another to be purified, can help compensate for the damage caused by another. The Church, who is made up of all the saints, is said to collect a great 'treasury of merit', which she can 'apply' in particular circumstances, to relieve people of the penances they would otherwise have to do on earth, on in Purgatory. All of this is only a metaphor, of course, but it expresses something very real – a power entrusted to the Church.