Well, when you completely reject a religion which insists on kindness and warmheartedness, how much does this show your support of these traits? Unless of course for one reason or the other you don't agree with parts of that religion, so you reject it, as it is wrong, but you acknowledge the parts that you find right. For example, there are religions (ie Buddhism I think) that have some similar teachings to Christianity (peace, harmony) in a different way maybe. I, as a Christian, do not follow these religions, but acknowledge how we end up having similar ethical beliefs, thus support them.
I don't know what you presonally believe, or what your ethics are, but Christian hate, or disrespect towards religious people, looks like an important part of the atheistic belief.
Well, if you don't believe in God, what motivates you to be kind and warmhearted? It all looks meaningless, and the existence of the different humans looks like a random natural phenomenon.