For many people, Christmas is the only time they enter a church, and the service can appear unfamiliar. So what can they expect, asks former vicar Mark Vernon.
Some 12 million people in the UK are thinking of going to church on Christmas Eve or Christmas Day according to a survey this week. That's about four times as many people as on an average Sunday.
Even if many of those who are considering stepping over the threshold eventually decide not to, Christmas is far and away the busiest time of the year for churches up and down the country.
For many in the congregations, Christmas is an important time to reflect on spiritual matters and church-going is a key part of this. But many others will be walking into a building that looks strange, for a service that's not familiar. So what will happen and what should they watch out for?
First, a warning. Contemporary churches can differ vastly from one another. Long gone are the days when every parish church had a heavy door at one end, a wooden altar at the other, and stained glass and stone arches spanning the distance in between. Don't be surprised if the building you enter looks, to the untrained eye, more like a conference centre hall than something out of Four Weddings and a Funeral.
EIGHT CHURCHGOING TIPS
1. The numbers on the wall are hymn numbers. Cross-reference to the book in your hand
2. Sit, stand and kneel as others do. It's OK to sit when they kneel
3. Find a seat to one side and a little way back, so you can copy others when unsure
4. Feel free to take communion, though some churches may offer you a blessing
5. At the sharing of the peace, go with the flow. Most churches will at least shake hands
6. Dress smart casual
7. Don't stress if you're late. Sneak in at the back
8. Midnight Mass doesn't necessarily start at midnight. It might begin as early as 8pm. Check church website
That said, what you see will tell you much about what to expect - and what might be expected of you. Look around. The fixtures and fittings are clues.
If you see crucifixes and statues, a decorated altar and candles, and you catch the tang of incense on the air, then you're in a high church. It might be Roman Catholic. Or if it's Church of England with smells and bells then it could be so-called Anglo-Catholic.
In both cases, the climax of the Christmas service is Holy Communion. Also known as the Eucharist or the Mass, you'll be invited to receive the bread and wine in an "Anglo-Catholic" church, so long as you count yourself Christian; and you may receive in the Roman Catholic church, so long as you are a Catholic.
Otherwise, feel free to go forward, bow your head, and receive the priest's blessing.
Choose a high church if you enjoy colour, music and liturgical action. The sermon will be short too: 15 minutes is generally thought excessive. Also, go here if you want a bit of anonymity, because you'll probably be able to come and go without having to negotiate more than a smile in welcome.
We live in an age of choice, and religion is no exception
Those actually keen to mingle with members of the congregation might prefer a low church. The fixtures and fittings to watch out for here include the following.
There will be a cross, though the figure of Jesus won't be on it. At the front is a pulpit or lectern. There will probably be a small church organ, though there may also be a drum kit and microphones assembled centre stage too.
There'll be no exotic smells and the room will tend to be evenly and brightly lit.
You're in a building at the conference centre end of the ecclesiastical spectrum. A low church like this may be Church of England or it may be another denomination, perhaps Methodist or Baptist. If you can see a drum kit, it could be Pentecostal, which means modern music and the raising of hands in praise.
Don't be alarmed. You don't have to be so moved yourself, though the heartfelt melodies are designed to be irresistible.
Some churches are more ornate than others
Apart from the singing, the focus is the sermon. In a low church, the sermon will tend to be longer. Choose this venue if you enjoy singing, an intellectual challenge and a hearty, Christmas welcome.
Falling in between high and low churches comes middle of the road Christianity. Almost certainly Church of England, this is the kind of service that features in TV shows like The Vicar of Dibley. The visual cues speak of a third way too. There will be a crucifix or two, a candle or two, a modestly decorated altar, some stained glass and a few arches.
The carols will be traditional, perhaps with the addition of a modern song. The sermon will be of modest length and generally liberal mood, with a suggestion about how the Christmas message can help us live better. There will be Holy Communion, though without much ceremonial. The vicar may be male or female. In short, this service presents a more gentle spirituality.
Churchgoing can be daunting: we live in an age of choice, and religion is no exception. But wherever you go, bear in mind Christmas is a season of goodwill. You will be welcome, even if you feel something of a stranger.
Mark Vernon is author of Plato's Podcasts: The Ancients' Guide to Modern Living, published by Oneworld