What is the difference between the family of God and the church of Christ? Not all believers of Christ are members of the church of God. All the saved belong to the family of God. The family of God is composed of all the saved from the time of Adam to the present time, and all who would accept Christ by faith will be added to the family of God. If a person is not a child of God, then he is a child of the devil and is not a member of God's family (John 8: 44, 47). When a saved person follows Scriptural baptism, then he is added to the church of Christ. Acts 2: 41, 47. The church of Christ is composed of all the saved and scripturally baptized believers who are assembled in a particular location. There are certain identifying marks of the Lord's church.