“For God has put it in their hearts to execute His purpose by having a common purpose, and by giving their kingdom to the beast, until the words of God will be fulfilled.”
This is a passage that many Calvinists hold up as a proof text for determinism. It is especially brought up when non-determinists fault Calvinist determinism for making God the author of sin. The determinist will then counter with a passage like this to demonstrate that God does cause people to sin or control their wills to do evil (though most will still claim that he is somehow not responsible or blameworthy for the evil he irresistibly causes us to do). I would, however, suggest that this passages teaches nothing of the sort for the following reasons:
First, the passage does not say that God controlled their wills to evil. It only says that He put it into their hearts (or minds) to share a common purpose. This common purpose was secured in the fact that they gave their kingdoms to the beast. The passage does not say that the kings necessarily yielded to what God put in their hearts to do (i.e., God did not control their wills irresistibly, but only influenced them).
Second, their wills and desires were already in line with those of the beast so God did not influence them to sin (since He did not give them those desires). They were already in allegiance with the beast in their hearts before God put it in their hearts to give their kingdoms to the beast. God only influenced them to make tangible the allegiance which was already in their hearts so that God could accomplish His purpose. The transference of power is not immoral in and of itself. That is all that God influenced them to do. Any evil motivation for that transference of power or allegiance was not caused by God, but already resided in the hearts of the kings.
Third, while verse 13 tells us that these kings gave their authority to the beast, the emphasis is on the fact that God put it in their hearts to exercise their power in line with the purpose of the beast (i.e., to cooperate with him to accomplish something). And what was that purpose? This is the key to understanding this passage. Verse 16 tells us what God was trying to accomplish:
“And the ten horns [kings] which you saw, and the beast, these will hate the harlot and will make her desolate and naked, and will eat her flesh and will burn her up with fire.”
God put it into the hearts of the kings to be of one purpose with the beast to destroy the whore of Babylon. God was using the beast and the kings to exercise divine judgment on her (who probably represents the corrupt world system). So God put it in their hearts to do His will, which was to destroy Babylon (the great harlot). Was the destruction of Babylon a bad thing? No. It was a good thing for Babylon to be destroyed, an act of divine judgment, and it was that alone which God put into their hearts to accomplish. So God actually put it in their hearts to do a good thing, even if their intentions were not good!
Fourth, even if God had irresistibly influenced them to be of one purpose it does not follow that this is always how God operates. Indeed, the fact that the text specifically tells us that God put it into their hearts would seem to suggest that this is not how God usually operates. If God always controls man’s thoughts and will, then there would be no need to make a point of it here. The fact that the text makes a point of God’s involvement suggests that this is not always the case. So the text fails to support determinism in general or the idea that God irresistibly determines the wills of His creatures to do evil.