The Larger Catechism expresses it as follows:

Q14: How doth God execute his decrees?

A14: God executeth his decrees in the works of creation and providence, according to his infallible foreknowledge, and the free and immutable counsel of his own will.

In other words, God works out his eternal decree through Creation—i.e., the creation of second causes— and through Providence—i.e., the outworking of second causes. While providence does not preclude miraculous intervention, the normal outworking of providence is through second causes that “fall out” of the creation as God made it in the beginning. In other words, God miraculously made the birds and the bees in the beginning, and since the beginning birds have made more birds and bees have made more bees—according to the second cause of biological reproduction. God makes the “kinds” and afterward the “kinds” reproduce after their own kind.

Here is where we want to make the clear distinction: before second causes can operate, they must first be created. Hence, creation must come first and it must include those things that, by definition, are not secondary causes. So we see that creation is all first cause (miracle) and no second cause. When viewed in this way, creation necessarily excludes supposed “processes” like evolution. We mustn’t project our scientific bias for the operation of secondary causes onto the miraculous first work of creation.

The ongoing work of providence includes preservation—inasmuch as existence (ontology) is not an inherent property of anything except God. And the creation is preserved in order for God to work out his purposes in it: and nothing in his creation can stop him. God is never limited by anything he makes. He can therefore act without, above, or against his creation at his will (WCF 5.3).

Perhaps our most important takeaway (expressed succinctly in WLC Q/A #18) is that God governs his entire creation all the time. There is no time or place where God does not exercise his absolute authority over his creation. And one of the most remarkable expressions of his goodness is his sovereign determination to bring good out of all evil. In the good plan and good purpose of God, all evil has a good purpose: to bring glory to God.