The existence of God. That surely has to be the big one. Is there a God? As a child growing up in Ireland in the 1950s there was no question about it. God existed and the local Catholic priest had the key to the God question. The Irish Catholic Church had its pulse on God. If you were not in agreement with Rome, then your were in error.
Flashbacks to that time recall a scheme of things that made the entire God question simple and straightforward. It was in many ways as if God were a citizen of an inward-looking Ireland and God was completely on the side of the Irish bishops. They knew what God was thinking.
But back to the God question. Is there a God? Do you ever ask people at parties or at work if they believe in God. You get many answers. Some say yes, others say no and more say yes, but add riders. In many cases it is not the God of their childhood or the God of the Catholic Church. They might even add that maybe this God is more a spiritual power than anything else.
In a few days time we will celebrate the birth of Jesus Christ. We are celebrating and acknowledging the fact that Christ was and is God. That is truly an amazing phenomenon. We may read and study all we like, but in the end it is very much a question of faith. And when it comes to faith and belief, we can take nothing for granted. We have to be forever avoiding cliches, ridding ourselves of the status quo, never allowing ourselves to be part of a "gang". Instead, we have to think for ourselves. We have to ask ourselves if we believe in God.
And once we utter God's name we are in the realm of the beyond. Indeed we can talk about an imminent God, we can refer to our brother Jesus, but ultimately God is away out there. We have to be aware of the transcendence of God. And maybe in some ways we have lost the sense of a transcendent God.
John the Baptist, when asked by the priests who he is, has no trouble in admitting that he is not the "prophet". He quickly points out that he is unfit to undo the sandal strap of the prophet. But he admits that this great prophet, "stands among you - unknown to you".
In these last days of this millennium we are in many ways no closer or nearer to answering the God question. But in the middle of all the doubt and wonder there are glimpses of light. Isaiah tells us that he rejoices in God for he has clothed him in the garments of salvation. He has sent him to bring good news to the poor and to bind up hearts that are broken.
The celebration of the birth of Christ is very much linked with making that God out there real and tangible in our lives. That will involve all sorts of unanswered questions, create all sorts of contradictions. But celebrating Christmas is in many ways the beginning of the journey of our attempting to discover the Almighty.
The goodness in the world about us has all to do with God; somehow, when we can see the link between goodness and God, surely we are on our way in answering the God question.
It can be tempting to have a very narrow and naive idea of God, but to dismiss the God question out of hand surely is an absurdity.