Can you say something is objectively wrong without religion?

This post is NOT about a specific religion. I know that many religions that claim to have objective morality don’t actually in reality, but that is not what I am talking about.

I am asking if, in order to say that one system of morality is better than another (in other words, that some things are objectively wrong or right), do you need that morality to be grounded in something metaphysical, spiritual, or religious? Otherwise, how can one human-based moral system be said to be better than another? The only way it could is if that moral system is based in something that goes beyond humanity (not that we can prove that it actually does, I am just speaking in principle).