The immutability of God means that God is unchanging. More specifically, "God is unchanging in his character, will, and covenant promises. Louis Berkhof's systematic theology text (a Reformed classic) defines God's immutability as 'that perfection of God by which He does not change in His being, perfections, purposes, or promises.' The Westminster Shorter Catechism says, 'God is a spirit, whose being, wisdom power, holiness, justice, goodness, and truth are infinite, eternal, and unchangeable." Those things do not change. A number of Scriptures attest to this idea (e.g. Num. 23:19; 1 Sam. 15:29; Ps. 102:26; Mal. 3:6; 2 Tim. 2:13; Heb. 6:17-18; Jam. 1:17)." [2]