What is actually happening to [believers in Christ] is that we are gradually being conformed to the character and likeness of Christ. As we invite His Spirit to come into our careers and into our lives we find that He then tends to produce His own characteristics in us. Instead of being tense and anxious and nervous we become more calm, confident, and relaxed. This is because we become increasingly aware that just as God our Father is very much in control of outer events in the world around us, He can likewise be in calm control of the inner turmoil of the world within us. Essentially this is what we mean by allowing ourselves to be led or guided by God. It is what we refer to as being under Christ's control. It is the thought of my spirit's being so in harmony with God's Spirit that there is a desire and willingness to do God's will.
-- W. Phillip Keller in “SERENITY: Finding God Again For The First Time”