<you can have the high moral principles of any religion without the need of belonging to it or believing in a God>
modeller
perhaps you are viewing this from the wrong direction?
ie
religions - moral principles - adoptors of those principles who don't follow the religion
evidence from across the broad spectrum of human experience is that there are fundamental principles which people display to varying degrees and which are encouraged by societies. those principles are connected with our desire and need to coexist in social groups and support each other
eg 'do as you would be done by' the 10 commandments, forgive your enemies, help the less fortunate etc
one consequence is that as religions have been developed by people over time, they have incorporated (and tried to take ownership of) those fundamental principles.
so it is no surprise that many people can enact those principles without any recourse to a religion