Right. But Jews and Muslims disagree, so how does all this "truth" get resolved, except to admit it is all relative and subjective, and free of absolute authority. Oddly it's all the same God.
the dilemma here is that this assumes all people are mature and love themselves. The angry, immature, and self-loathing will treat others the same way, and still be in accordance to what Jesus said.
I think most religions realy heavily on the natural goodness of people to work. What we see of a religion tends to be representative of the natural person. Bad theists tend to give rtheir religions a bad name.
My grandmother was presbyterian and she asked me to volunteer in her church's food kitchen. they served meals twice a week to the needy, and they would feed maybe 200 - 300 people, often families. None of the women doing this service ever said anything about religion. No prayers, not requirements, just service to their fellow citizens. That really made an impression on me. To my mind this is what Jesus meant by his church, not the ornate buildings with boring sermons telling us what kind of no good scubmbags we are not deserving of God's grace. The simplest truths tend to be correct.