I’m not being a smartass here. This is one of the most common questions we atheists get asked when discussing our lack of belief in gods, and it’s always asked as if it’s just assumed that there’s one answer and we’re supposed to know it. But even among Christians, there are many different conceptions about what the consequences of nonbelief are. Some seem to believe that as long as we’re good people we go to heaven when we die whether we’re Christian or not. On the other hand, we have those who believe we’re going to hell (although there are many different conceptions of what hell is) where we’ll suffer unimaginable torment for all eternity simply because we don’t believe.
Then you start looking outside Christianity, and you see many other conceptions of afterlives, and the consequences for those who do or don’t believe, or those who do or don’t act in certain ways with regards to the various pantheons.
So, in all seriousness, I don’t know. Tell me what you believe will happen to me, and we can go from there.
I will say, though, that most of the time (at least in America) this question comes from Christians who believe that we’re risking the eternal torment version of hell for the crime of not believing their god exists. The more aggressive ones phrase the question in terms of “What will you say to God when you die and have to face His judgment?” As if it were possible to threaten us into believing that for which we haven’t seen good evidence.
Of course, the first and easiest answer is that I have no more concern for that scenario than I imagine any Christian has for what they will say to Allah, or Thoth, or Hades, or the Valkyries (who, for the record, I also don’t believe exist). It’s hard to get worked up when a being you don’t believe exists threatens to send you to a place you don’t believe exists because you don’t believe it.
But then, I’ve been an atheist for a long time. I’m comfortable with it.
The thing that gets me about the question, though, is that it’s a dishonest tactic. It’s not about finding the truth; it’s intended to make you scared, so that the questioner can use that as leverage to open you up to the idea that they have the answers that will alleviate your fear. It’s creating a symptom so that you can claim to have the cure.
Though I’d have to believe that an all-powerful being would have more effective means than threats to get me to believe in it, and any being I’d respect enough to worship would be above making them.
So, what if I’m wrong? I don’t really know. Nobody actually does, and it’s not a question that can really be speculated on until someone can demonstrate that an actual consequence exists.