Adama would be dead too if it wasn't for constant divine intervention in the guise of citizens in his fleet constantly experiencing visions, having God-messengers in their heads which gave them the word of the almighty, and Starbuck being resurrected as an angel with the knowledge of what to do in order to get to Earth.
Cain had none of this and had to make the tough choices. If God hadn't for some entirel unexplained reason decided to bombard the Galactica with riddles, visions and resurrections then they'd be as dead as Cain. All of them.
That's true, but a lot of Cain's atrocities would have occurred even if she was
bombarded with riddles and visions. Raiding civilians, murdering her XO... those things occurred very early on. As was pointed out, Adama was also ready to abandon civilians and charge into battle, but decided not to. And this was before any of the mystical stuff.
It may be that Adama's group was offered those chances because of
their initial choices.