Love the Lord your God with all your heart, soul and strength. And love your neighbor as yourself. Jesus said these were the greatest commandments. Even if you're not "religious", it's not a bad place to start. Even if you don't believe in a god, you still have to recognize creation, life and be thankful in some way. And through that lens, we are to see that man is part of that creation, a very special part. The Word says we are created in His image. I'm not smart enough to parse that out... but compared to the rest of creation, humans are set completely apart, different. So I guess what I'm saying is that if we have a reverence for the Creator and we recognize our fellow man as His special creation, then we should treat our neighbor as such.