Jeremiah 32:27

(Verse 27) Behold, I am the Lord, the God of all flesh. Is anything too difficult (or impossible) for me? Or will any word be hidden from me? I am, she says, the Lord God of all flesh. Not at all of all nations, nor of the people of Israel, or certainly, as He is often called by the holy ones, the God of Abraham, the God of Isaac, the God of Jacob, but God said to all flesh, so that it is believed that He made both rational and brute animals Himself. For there are those who confess the providence of the Creator even up to rational beings: but they assert that brute animals either perish or live by chance events. And the prophetic speech declares that there is nothing that escapes the providence and knowledge of God; because some things are created for their own sake, while others are created for the use of humans. Is anything difficult or impossible for me? Or surely, will every word be hidden from me? And as we have said above: The things that are impossible among humans are possible among God. But we must understand the word here and in many other places to mean 'things.' 'What is it,' he says, 'that has happened?'

Of course nothing is "too hard for the Lord." But if we choose to apply this principle so extravagantly and harshly in our capricious imaginations, we may then make out God to have done anything we please, on the ground that it was not impossible for him to do it. We must not suppose, however, because he is able to do all things, that he has done what he has not done. But we must inquire whether he has really done it. God could, if he had liked, have furnished humankind with wings to fly with, just as he gave wings to kites. We must not, however, run to the conclusion that he did this because he was able to do it. He might also have extinguished Praxeas and all other heretics at once; it does not follow, however, that he did, simply because he was able. For it was necessary that there should be both kites and heretics; it was necessary also that the Father should be crucified. In one sense there will be something difficult even for God—namely, that which he has not done—not because he could not but because he would not do it. For with God, to be willing is to be able and to be unwilling is to be unable; all that he has willed, however, he has both been able to accomplish and has displayed his ability.