I can't believe the thread has gotten this far without someone asking "How are you?"
The best response to actually tell someone how you feel. They don’t really want to actually know usually and it’s amusing to make people uncomfortable.
You've probably encountered Christians who answer the question with "I'm blessed". A assume they do so as a way of either (a) reminding themselves that their good fortune is a blessing from heaven, or (b) as a way to inoffensively identify themselves as a Christian. I think the overlap is probably large with the group of people who say "Have a blessed day". Anyway...
One lady in our church recently told me that she answers with "I'm blessed" when she's actually not doing very well. She doesn't want to lie by saying "I'm fine" when she really isn't fine. But there's also a good chance that either she or the person asking doesn't really want to talk about what's wrong. And so, because she believes it's an objective fact that God has blessed her even if she can't discern exactly
how at the moment, she has chosen "I'm blessed" as a way of technically not lying but still dodging a conversation she isn't keen to have.
So now, if I ask her how she's doing, and she says "I'm blessed", I respond with "Oh, what's the matter?"