The word generally used to describe becoming a Christian is conversion. It indicates a change of direction, an about-turn, a change of heart. It means entering into a new relationship with God in which unbelief is replaced by belief and trust, resulting in new life.
This new relationship brings great joy and many blessings. There is open communication between the individual and God: the pain of separation is past. We are aware of new desires for good and new power to realize them. We enjoy a sense of confidence in God's presence and feel that we are part of a new family. We long for more of God and his reality in our present and our future. Such blessings as these have been expressed in the language of Christian doctrine, for example: justification, regeneration, assurance, adoption and sanctification. The terms are important in identifying the nature of our personal experience and grounding it in the universal experience of Christian believers.
God's purpose in saving us is create in us the likeness of his Son. Jesus Christ, who is the true image of God, so that we may "participate in the divine nature" (2 Peter 1:4). It is to make it possible for us to glorify God as Christ's true disciples. It is to make us holy (Ephesians 4:22-24).