God's Immutable Plan

God's eternal plan must be immutable for a number of reasons. One, God himself is eternal and unchanging, and therefore, any plan that arises out of his nature must also partake of being unchangeable. Secondly, the prophecies of the Old Testament. God cannot deliver on his promises if he doesn't already know and control the way that history is flowing. If God changes his mind, then his promises in the Old Testament are hollow promises. Thirdly, that leads to a distinct pastoral point. The immutability of God and the immutability of God's purposes is a vital pastoral doctrine, because it's only if we know that God's plan is absolutely reliable, it's only if we know that God does not change, that he will always fight for his people, that he will always fulfill his promises for his people, it's only if we know that, that we can actually preach the gospel with confidence or apply it from one believer to another. So, I would say for biblical, theological and pastoral reasons, God's plan must be immutable.