Personal renewal or sanctification belongs to the heart of the Christian life and is becoming more important in our present-day culture. Listening to Scripture and in conversation with a variety of theologians from the protestant tradition, Willem van Vlastuin presents an up-to-date concept for a theology of personal renewal. In this concept the spiritual union with Christ considers the way in which renewal obtains form in relation to God, our neighbour, ourselves and the world. The author places this concept into a historical perspective. Furthermore an important issue concerns the measure of renewal, especially in relation to the sinful heart of the believer.