All of the aforementioned systems of beliefs in some way represent the idea that faith in God alone is enough to get anyone into heaven, so long as it is part of their destiny. However, there are two basic problems with this premise, the first being that a Christian who follows it or who claims to follow it can more or less justify living outside of the rules of traditional Christianity and can also justify doing anything else that they want, including things that would normally be considered sinful, just as long as they have faith in God (since faith in God is the only core requirement of Calvinism, for instance). I would even go as far as to suggest that they might not justify going to church since it may as well not be necessary in lieu of a simple faith in God.

A second issue is that those Christians who are part of a different Christian denomination could take a page out of the book of Calvinism and decide that there is no reason why the premise can't or shouldn't apply to them as well, since anything short of this would be unfair and present an uneven playing field among Christians in general.

Also who or what is to decide the details of a person's destiny in terms of predestination, and how would could it be determined if this is true, as opposed to simply being made up based on opinion of a person? The entire premise behind this idea is inherently flawed, as there are too many hypotheticals and eventualities to take it seriously in any way.