David Wells wrote a book on conversion called Turning to God: Reclaiming Christian Conversion as Unique, Necessary, and Supernatural.
He describes conversion with this statement:
Christianity without conversion is no loner Christian, because conversion means turning to God. It involves forsaking sin, with its self-deifying attitudes and self-serving conduct, and turning to Christ, whose death on the cross is the basis for God’s offer of mercy and forgiveness. Jesus was judged in our place so that God could extend his righteousness to us. Conversion occurs when we turn from our waywardness and accept Christ’s death on our behalf.
And then he goes on to speak of what he calls, “The Life of Convertedness.” (Ibid., 42.)
Conversion is not an isolated event but is related to the entire life of faith that follows from it. It is the moment of birth into a new life. It is like a doorway into a room. A person is born to live, not to linger on the edge of the womb in a time of limbo. A person opens a door not for the pleasure of standing forever on the threshold but to enter the room. The evangelical world has strangely perverted this truth. Evangelicals often make the test of spiritual life one’s willingness to testify about the moment of birth. Describing one’s sensations in passing through the doorway is considered proof that one is in the room! . . . The only real proof of our conversion is an obedient and fruitful life. (Ibid., 43.)
The point about conversion, though, is that it is the way into Christian faith; it is not the entirety of Christian faith. Conversion is only the threshold to the building of salvation. (Ibid., 22.)
Christianity is inescapably preoccupied with changed lives. (Ibid., 45.)
Conversion denotes a transformation from self-dedication to dedication to God. (Ibid., 45.)
Conversion results in a religion that becomes socially tangible. (Ibid., 47.)
Above all, conversion implies a movement from theory to practice. (Ibid., 47)
The reality of conversion witnesses to God’s lordship . . . and is not just a figment of metaphysics. (Ibid., 48.)
In the Christian world today, however, what we have all too often is an aberration–spiritual birth that is not followed by an obvious spiritual life. (Ibid., 23.)
When Jesus issued the Great Commission, he did not tell his followers to go into all the world and ask people to raise their hands or to fill out a decision card. Rather, he enjoined them to make disciples, baptizing them and teaching them to obey everything he had commanded. (Ibid., 10.)
Just as there is no discipleship without conversion, so there also can be no conversion without discipleship. The two belong together. (Ibid., 23.)
 David F. Wells, Turning to God: Reclaiming Christian Conversion as Unique, Necessary, and Supernatural (Grand Rapids, MI: Baker Books, 2012), 27.
 Continued, “This truth is most clearly taught in the parable of the sower and the seeds (Matt. 13:3-23; Mark 4:3-20; Luke 8:4-18).”