@susanc
I think that @Mamradpivo is saying that since your question asks “If God existed…”, etc., then in that hypothetical situation it would no longer be a matter of belief, but rather of deciding whether or not to go along with God’s vision of love. That decision would seem to be a no-brainer.
But since as things stand the whole matter of God’s existence is in doubt, that compelling vision of a loving God may just be a fiction. Then the question becomes one of faith: am I willing to base my life on a version of reality that I can’t verify intellectually?
There are certainly worse way to spend one’s life than in service to the ideal of universal love. I personally don’t believe that one necessarily has to posit a God to make that work, but hey, if that makes a difference for some folks, then I’ll not argue. The unfortunate truth , of course, is that few people share this purely benign vision of God.