WCOF V:II

II. Although, in relation to the foreknowledge and decree of God, the First Cause, all things come to pass immutably, and infallibly;^h yet, by the same providence, he ordereth them to fall out, according to the nature of second causes, either necessarily, freely, or contingently.ⁱ

(h) Acts 2:23; Isa 14:24,27
(i) Gen 8:22; Jer 31:35; Isa 10:6-7; Exod 21:13; Deut 19:5; 1 Kgs 22:28-34

God decrees all things, yet, all things occur in accord with free will. This is one of the most difficult mysteries of the scripture: God infallibly determines whatever happens and yet people act freely.