Our sense of morality, right & wrong, etc. evolved in tandem with our big brains and highly social behavior. We are far more successful creatures when we work together within a framework of common interests and good. Here we are, dominating a planet after a mere instant of geological time. It took other creatures tens of millions of years to similarly dominate their environment. You can't argue with success! Luck too; had that asteroid missed by a hair, it's anyone's guess what the natural world might look like today.

Various religions have done a decent job (with notable exceptions..) of codifying morality - credit where due. But so did philosophers, poets, songwriters, etc.