I would say that is also correct, but not a replacement for "God cannot lie". In both cases, God so doing would be for Him to act wholly in contradiction to His pure nature. I don't think that is possible. In addition, if we say that all power everywhere in the universe comes originally from God, then by definition, He cannot lack any of it. IOW, we could ask "does God lack the power to become satan?". We would answer "no, but God cannot become satan, or else, He wouldn't be God. He would be ....... something else".
I understand what you mean by "wouldn't" and that is also true. Perhaps it just comes down to who God is on a definitional level. If He is defined as unchangeable and sinless, then He can't sin. I think God supports both of those definitions in His Holy word.
[On Jesus asking for the cup to be taken away:] But again, there's the problem of speaking about His obedience as though it were a limitation rather than an accomplishment. If it were me in the garden, I'd probably say, "Get yourself another boy, I'm outta here," but that would be my failure.
I suppose I don't see it that way. Jesus was 100% man, and the instinct of men is self-preservation. He showed the instinct, and His accomplishment was in the surpassing of it by overcoming it. No limitation at all. :)
Makes his willingness to go to the cross all that much greater. What Amazing Love.
When I "check my work" on theology and stuff, I think it good to "savor" every articulation, and to sniff out all the (apparent, if not real) tensions and seeming contradictions.
For example IF Jeremiah says (Lamentations 3:33) that God does not willingly afflict or grieve the children of men, the sheer wonder of how an inspired prophet could make the suggestion that God does something "unwillingly" ought not, I think, to be explained away with a bunch o' talk about contingent will and this will and that will. That the Holy Spirit could think for a second that a good way to talk about God is to portray Him as doing something unwillingly, well... hush my mouth! That's amazing.
And so with God "cannot" lie. The strict sense of "cannot" is a limitation on ability, as though, well, He tried as hard as He could, but He just couldn't do it.
But a circle "cannot" have corners. That inability is, as it were, the glory of the circle - no matter how closely we look at it, it always curves with the same rate of curvature .... No jaggies.
So I am looking at the statement, God cannot lie, and trying to find another way to express the same truth without a suggested negative, is all.
No, it's okay. I LIKE lowering my head and running into brick walls. Sometimes I learn something, even if it's only, "Whoa! That there is one tough wall!"
And I think we agree about IHS and the obedience. 100% Man qua nacheral critter, with or without Fall, wants to live. 100% Man qua (allegedly) rational animal deduces that the fulfillment of all his desires is in God's Will, and wants what God wants. 100% unfallen or full of Grace, natural, rational, human-type personnel sees clearly what the merely rational Man sometimes deduces vaguely, and doesn't have to worry about rebellion of the "members" trying to talk Him into rationalizing disobedience.
And once again it seems that if we want to see what the fullness of God's wisdom, power, justice, beauty, and joy are, a man on a cross is NOT a man limited, but the Son of Man blossoming as one who came to do God's will.
NOT in any meaningful way a limitation.
At the end of the Memorare, a prayer to the virgin supposedly by St. Bernard - he of the brandy cask around the neck - no, maybe that's someone else, those of us who like furrin or dead languages pray: audi propitia et exaudi. Hear prayer and REALLY hear it. Which is usually translated hear my prayer and answer.
I mention this because "obey" is, at its heart, an intensive of the verb audire, so, "listen intently" (as a servant might listen to an exigent master.) The Word listens intently to the Father's words, and this is not a limitation but His Glory.