The doctrine of God's eternal decree is essential to our understanding of systematic theology, because it is this doctrine that helps us define and explain the sovereignty of God, that God has decreed all things whatsoever come to pass. There is nothing that surprises God. These things happen because of God's decree. Of course, the subsets of that and the ways he works out his decree are through his works of creation and providence. And so the way he created the world, the attributes that he has given the world, and the way that he sustains the world and keeps it being what it is – the earth stays the earth, it keeps spinning in the same direction, you know, all of these things stay the way they are by God's eternal decree – and in his works of providence, the way that God works within the lives of his people and within his creation in order to cause them to act in according to the way that they were made, and to fulfill his decrees, this is the way that we understand God exercising and executing his sovereignty in the world. And so, because of this, we believe that all things work together for good to those that love him and are called according to his purposes. Why can we believe that? Because we believe in God's eternal decree. We can say that we know that all things are going to work out the way that we find them in Scripture. Why can we say that? Because we believe in God's eternal decree. God is not hoping to work the world out. God designed the world exactly as it is, and it is doing and being everything he intended it to do and to be to maximize his glory.