I am of the belief that we should be kind to others, if only because we would want them to be kind to us, regardless of if there is some divine force that tells us to. Many animals have morality, though in a limited sense, and don't have religions as far as we know (Source: http://blogs.reuters.com/faithworld/2009/06/19/do-animals-have-moral-codes-well-up-to-a-point/). Additionally, Albert Einstein didn't believe in a singular God, " I do not believe in a personal God and I have never denied this but have expressed it clearly." Also, he said, "A man's ethical behavior should be based effectually on sympathy, education, and social ties and needs; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death."(Source: https://www.learnreligions.com/albert-einstein-quotations-249858).