Why God doesn't stop satan?

[Angrboda]

Or, to put it more radically, anything you consider to be true is only true for you. If there is no absolute reference of truth (i.e. God), nothing you say has any truth value whatsoever.

You are in the same position. A) You don't have access to God. B) Even if you did, your belief in its absoluteness would be dependent upon you, not God.

You must have encountered a similar argument related to morality, there cannot be an objective morality without a supreme moral entity. Even if one says that well-being or minimzing suffering is an objective criterion of good moral actions, one can simply keep asking what makes this criterion superior to other competing criteria, etc.

The same applies to God. Does Euthyphro ring any bells?

I should note I am not a fan of these arguments, because they resemble presuppositionalism. But presuppositionalists have a point, though: the premise "God exists" seems to solve hard solipsism. No other premise can do that.

No, it just adds another belief that the solipsist believes in.