by Matt Slick
In one sense it is possible to mess up God's plan for your life, but in another, it is not. God is not surprised by anything you do, and everything that happens in your life is within the will of God. Let me explain.
Ephesians 1:11 says that God works all things after the counsel of his will. This means that everything that occurs in your life, all your free will decisions, all your choices, all your intentions, all your mistakes, all your sins, etc. work within the divine knowledge and will of God. Nothing is outside the scope of God's knowledge, and no one can do anything that surprises God.
Nevertheless, in theology we sometimes talk about different aspects of God's will. In one sense he has a decretive will. This means that God decrees and or directly causes certain things to occur such as the creation of the universe, the incarnation, etc. Then there's another aspect of God's will that we call the prescriptive will. Think of the word "prescription." In God's prescriptive will, he says do not lie, do not commit adultery, etc. (Exodus 20:1-17). This deals with his moral will for us. He does not want us to sin. Then the third aspect is God's permissive will. In this, he wills to permit us to sin. Though he does not want us to, he allows us to.
So let's return to the question.
In one sense we can mess up God's plan for our lives by sinning in rebellion against his calling and purpose for us. But on the other hand, he knows that we will deviate from his prescriptive will (the don't-sin will) and, of course, since God knows all things (1 John 3:20), he even works our sins into his overall plan (Eph. 1:11). So, though we might in one sense be out of his will, we are in another sense always within his will.
But generally speaking, people want to know something a little bit different. They want to know if God has a specific plan for their life and whether or not the person can mess that up. Well, I suppose that's possible if we were to understand that God might have placed a calling on someone's life and the person purposely rebels against that calling. In that sense, a person could mess up God's plan for his life. But even then, God is sovereign and can work with it.
I hope that helps.