What is free grace theology?

[Mem]

It’s entirely possible according to Peter and it has happened many times to many people, including some Bible characters.

So I’ll ask you again. Are you allowed to sin as much as you want? A simple yes or no will do.

2 Peter 2
20If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and are overcome, they are worse off at the end than they were at the beginning. 21It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them. 22Of them the proverbs are true: “A dog returns to its vomit,” g and, “A sow that is washed returns to her wallowing in the mud.”

The "if" Peter uses here is...

1487 ei (a conditional conjunction) – if. 1487 /ei (followed by any verb) expresses "a condition, thought of as real, or to denote assumptions" (i.e. viewed as factual. for the sake of argument) (BAGD). Accordingly, 1487 (ei) should not be translated "since," but rather always "if" – since the assumption may only be portrayed as valid (true, factual).

So Peter is saying that "if" that (condition) were true, then this assumption (worse off) would be valid. He's merely illustrating by hyperbole the actual state these people posing as saved are in but what can, actually, be "worse" than their fate as it is.

Peter's argument is that "if indeed (though more unlikely that) these have been saved, then they are no better off, their end is no different than before they were saved and they relate more to dogs and sows than they do to mankind.

Peter struggled with cursing, and it seems here that old habits indeed do die hard.