The following passage from Concluding Unscientific Postscript embodies a penetrating insight:
. . . the legal authority shows its impotence precisely when it shows its power: its power by giving permission, its impotence by not being able to make it permissible. (p. 460, tr. Swenson & Lowrie)
My permitting you to do X does not make X permissible. My forbidding you to do X does not make X impermissible. My permitting (forbidding) is justifed only if what I permit (forbid) is in itself permissible (impermissible). And the same goes for any finite agent or collection of finite agents. A finite agent may have the power to permit and forbid, but it cannot have the power to make permissible or impermissible. Finite agency, then, betrays its impotence in exercising its power.
For example, the moral permissibility of killing in self-defense is what it is independently of the State's power to permit or forbid via its laws. The State cannot make morally permissible what is morally permissible by passing and enforcing laws that permit it. Nor can the State make morally impermissible what is morally permissible by passing and enforcing laws that proscribe it.
Here below Might and Right fall asunder: the powerful are not always just, and the just are not always powerful. But it would be a mistake to think that the mighty cannot be right, or that the right cannot be mighty. The falling asunder is consistent with a certain amount of overlap.
Power does not confer moral justification, but neither does impotence. (For example,the relative weakness of the Palestinians relative to the Israelis does not confer justification on the Paestinian cause or its methods.) See The Converse Callicles Principle: Weakness Does Not Justify.
The State is practically necessary and morally justifiable. Or so I would argue against the anarchists. But fear of the State is rational: its power is awesome and sometimes misused. This is why the State's power must be hedged round with limits.
We don't know whether or not God exists. But we do know that nothing is worthy of being called God unless it is the perfect harmonization and colaescence of Might and Right, of Power and Justice, of Will and Reason.
Tough questions: Could such a transcendental Ideal (in Kant's sense) be merely a transcendental Ideal impossible of existence in reality? And could anything impossible count as an ideal? But if God is possible would he not have to be actual?