Science is descriptive, it cannot tell you how to behave towards the world.

If I have a gun, science can tell me what happens if I pull the trigger while pointing towards another person, it cannot tell me if I should or should not do that.

Ultimately any moral system rests in an axiomatic basis. If you believe that there are "right" and "wrong" actions, and things that are "good" or "bad", and if you try to explain why some things are good/bad eventually you'll be reduced to a set of axioms, e.g. "thou shalt not kill", "do not do to others what you don't want done to you", etc.

These axioms cannot be explained by science, because again, science is descriptive.

S Of course you can just keep the axioms and say that religion is meaningless, but then I don't see ho