How did pre-Abrahamic believers come to know the Father?
I know that Romans 1:20 tells us that all people can see proof of the Father in creation itself (the earth and sky), but barring this, how exactly did those that the Father found righteous, yet came before Abraham, come to know the Father? Did Adam pass down his knowledge of the Father down his family line? I know Noah was found righteous; was this simply because the Father spoke to him like He did many other people in the Bible?