What are the decrees of God?

God's decrees are the wise, free, and holy acts of the counsel of his will,[1] whereby, from all eternity, he hath, for his own glory, unchangeably foreordained: Whatsoever comes to pass in time,[2] especially concerning angels and men.

1. Eph. 1:11

   In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will...

   Rom. 9:14-15, 18

   What shall we say then? Is there injustice on God's part? By no means! For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.”
   
   So then he has mercy on whomever he wills, and he hardens whomever he wills.

   Rom. 11:33

   Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!

   
   
2. Eph. 1:4, 11

   ...even as he chose us in him before the foundation of the world, that we should be holy and blameless before him....
   
   In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will...

   Rom. 9:22-23

   What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction,in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory...

   Psa. 33:11

   The counsel of the Lord stands forever,
   the plans of his heart to all generations.

Question 12, Westminster Larger Catechism.
Scripture quoted from the ESV.