What were the key religious differences between the european nations that explored the americas?

Well, it all depends on what religions we are speaking about. Like, there are the Lutherists, Calvanists, Puritans, Separatists and of course the Protestants and Catholics. So basically, the lutherists believed that there shouldnt be any indulgences (paying to take away sins and such) within the Catholic Church, then the Calvanists believed in Predestination, thats when your fate in sealed before birth as to whether or not your going to heaven or hell. Then the Puritans wanted to stay within the Church, but wanted to purify it, hence the name. The wanted to make it the  Pure Biblical Christianity, then of course the separatists  were basically an extreme form of Puritanism, they did separate from the church (hence the name) and became the Pilgrims, that we knew to have the First Thanksgiving (: