Here’s a helpful paragraph about God’s sovereignty from Blocher’s Evil and the Cross:
“[Along with secondary causes,] Holy Scripture also includes the decisions of free beings under divine sovereignty. In point of fact, if such realities were excepted, what would remain of human history for God to govern? The Wisdom writers recognize that to God belongs the choice that directs a man’s life (Pr. 16:1, 9), and Jeremiah echoes the same thought (Je. 10:23).
The New Testament confirms that God grants the repentance and faith that he commands. The apostle Paul makes the point clearly: ‘It is God who works in you to will and to act according to his good purpose’ (Phil. 2:13). This admirable formulation immediately blocks any attempt to get round it; if Paul had said only ‘to will’, some would have explained that ‘man’s part’ is to carry through to completion the impulse begun by grace; if he had said only, ‘to act’, others would have added, ‘on condition that we ourselves are willing to start with’. Paul does not waver: ‘to will and to act’! He can be almost ruthless: ‘So it depends not on human will or exertion, but on God who shows mercy’ (Rom 9:16, NRSV). Such a word is hard to many people; to others it is sweet.”
Henry Blocher, Evil and The Cross (p 93).