11. Can one just be baptized into Jesus and not join a church?

Baptism is a sign both of a person’s regeneration or new birth and of their entry into Christ’s spiritual kingdom. Since it unites the new believers to Christ, it also functions as the door to the church, which is the body of Christ. Through baptism the Lord adds new disciples to the body of believers, the church. Thus, they are members of God’s family, not left adrift as unattended spiritual orphans. JTL16 13.1

The church body is organized for service. Becoming a member of the body commits Christians to the missionary task of the church—carrying the gospel to all the world. Membership in that body involves “forbearing one another in love,” being “eager to maintain the unity of the Spirit in the bond of peace” (Ephesians 4:2, 3). JTL16 13.2