God is omnipotent, but there are limits to what he can do. Because he has given man a free will and has chosen to partner with us to build his kingdom, not all that God desires to do will be done. Foster reminds us that "prayer by itself is severely limited in the good it can accomplish" without our obedience and participation with God.
Foster shares three major areas from Dallas Willard that God uses in our continuing formation. First, is the "classic disciplines of the spiritual life." These include solitude, fasting, worship, and others. Spiritual disciplines can often be a form of obedience in prayer. These activities can also prepare us for formation. Similar to digging up the soil for planting. The second area is "our continual interaction with the moving of the Spirit of God. Willard includes here "resistance, disobedience, repentance, submission, faith, obedience, and more." Our actions have a direct affect on the results of prayer and the formation that will occur. We are to take an active role in the process. Let me just pause here and compare this process to the Old Testament law. There was a very specific process the priests had to follow to obtain atonement for the sins of the people. We sometimes miss the New Testament equivalent pattern. Paul gives us an example in Romans 12:1-2. If we want a renewed heart, then we must present our lives as a living sacrifice. Its the same with our formation through prayer. If we want to see God work in us, then we must be sensitive and obedient to the Spirit's leading. The third area is the "patient endurance God develops in us by means of various frustrations, trials, and temptations we face daily." Just like practice makes perfect so endurance makes us stronger and overcoming produces spiritual formation.
Foster is making the point here that God intends for prayer to be an active and dynamic process of transformation. God has predestined us to be conformed to the image of his Son (Romans 8:29).