From an Islamic point of view Allah says in Quran (51:56) Pickthall: I created the jinn and humankind only that they might worship Me. …. read more
Adam and Eve (if taken literally) were in direct contact with G-d. They did not need any interpretive hierarchical religion to interact with G-d. So, they did not have a religion. As the gentleman posted earlier, the closest thing to "religion" that Adam and Eve practiced, was "submission to G-d." This is a central tenet in Islam. read more
Adam and Eve did not have a religion -- no set of rules which is what "religion" means -- except one. They had faith that God would take care of them and He did. Adam and Eve worshipped God. The one rule they had was not to eat the fruit of that one tree, but they disobeyed and ate from it -- both of them -- Eve was deceived by Satan. read more
If you want to be technical, what religion did anyone have until the second century ce as the idea of having a religion was a creation of Xanity. read more