If there is no God, why do I feel such love for those who don't believe in Jesus Christ?

I am the first to admit that there are many people who profess to be Christians but do not show the love of God. I know though, many Christians who feel the same as I do - love for people who scorn and ridicule us. That is not human nature. So then, you tell me - where does this love for you come from if there is no God?