I have a blog? I have a blog. It appears I have a blog!
Christmas is a family time, and for some holds religious significance. A lot of atheists have theist family members and the subject of god often does make it's way into conversation. You're sometimes put in the difficult situation of defending your lack of belief politely and without causing offence, and often a direct defence of atheism isn't appropriate. The direct approach assumes the person you are talking to can think objectively and has perhaps some knowledge of science or even of their own holy book. It can also be rather confrontational.
Some people have a strange idea of what evidence is, or what science is. Some people place a lot of weight on what is written in scripture or think if a large number of people believe in something that makes it more likely to be true. Or if people are willing to die for something it makes it more likely to be true. It can be frustrating sometimes but if these are the tools you are forced to work with, then so be it.
The alternative approach (e.g. for a Christian) is: "What about Judaism or Islam?" or "Can I be a Muslim?" The differences between those three religions are so minor that it's impossible to mount any kind of argument for one in preference to the others. The full range of pseudo-scientific non-truths as well as the 'God works in mysterious ways' card cuts equally well in all three directions. Should it be used; real science and objective reasoning can ridicule one just as well as ridiculing the others. No matter the tools, arguments or methods used by a proponent of one; the same tools, arguments and methods can support the others. Discussion is also kept civil as it's somewhat of a social taboo to negatively criticise one of the big three, unlike atheism which being a non-belief isn't afforded the same protection.
The ultimate conclusion is they are all 'equally wrong' (or 'equally right'). You can't be expected to follow a specific brand of theism if it's not possible to decide what you 'should' be. Being polite it's possibly best to leave it at that.
Maybe best not to mention how any good and just god who sends you to hell should you incorrectly choose, through the circumstances of your birth or your own free will, which of the mutually exclusive and 'equally right' religions you wish to follow must be evil - contradiction.
Hope you enjoyed reading.