Someone once asked...
Someone answered with kindness...
I wish you could have given more context for this, I assume because of the message that you are not an atheist. Coming from someone who is agonistic (does not have a specific faith but does not discount the possibility of a creator, ect) and feels somewhat the same way talking to religious people, all I can say is just, be open minded. You don't have to agree with any of their opinions but hear them out if they want to talk about it, you might learn something about them or about yourself. Another thing is, if you feel awkward because they keep bringing up religion, or them being atheistic, tell them to stop. Your friendship can exist even if you have differences, talking about them is good, but if it makes you uncomfortable, you don't have to.
Wandering voices — answers no one has read yet
Another soul answered...
If it feels weird to talk to them because they are an atheist, then the talking may have been part of the reason they are now. They are still a person, they are still a friend, and they are still in need of kindness and love. (I'm assuming you're Christian but even if you aren't my words will still be true) Jesus told us to show him in action most of all. Many atheists become so because of the behavior or words of the religious folks around them. Treating them differently or feeling weird about them is only proving them right in becoming an atheist. Jesus doesn't tell us to show love and talk to only our Christian brothers and sisters, but to all (Matthew 6 I believe goes into that specifically.) Treat them the same as anyone else, and love them as much as you possibly can. You cannot make them not an atheist, but you can love them so much that they pursue that love back to Christ. It is up to them to believe again, it is up to you to love them now and not treat them poorly or differently.
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