>>7303
The basic biological urge to form a pack. Basic decency can be considered the fundamental rules a person must follow if he is to work well with others and form a stable group. That includes respect of property not considered communal, respect of another person's life unless they've wronged the group, etc.
It certainly didn't come from a god, much less the christian one. Our western ideals of ethics and morality come from the enlightenment period. Morals predate the christian bible but the ideas of inalienable rights were not a widespread concept which is why even christians practiced things like slavery. It's easy to forget that the world was actually a pretty brutish place if you had the misfortune to be born in the wrong group of people even as early as 500 years ago.
>"But the enlightened thinkers were christian!"
They were deists, by and large. Which the overwhelming majority of christians would consider heresy. Being an ideology based primarily on reason it slowly lost ground as our understanding of the universe increased. Deism denies scripture and dogma and is skeptical to the supernatural events described in holy texts which many christians today would consider absolutely essential.