We use the religious phrasing for those because most of our children were raised with Christianity in past generations, but the sentiments in those phrases are as old as the hills and have been reiterated with slightly different wording by virtually every religion on the planet, and also by all sorts of secular parents who teach their children concepts for interpersonal behaviour like 'reciprocity'.

We can still educate our kids on those principles without the religious trappings ... and do.