This lesson provides an overview of water baptism as an essential component of the preaching of the Kingdom of God and Christian initiation. It traces how repentance, faith, and water baptism were inseparably linked in the ministries of John the Baptist, Jesus, and the early Church, emphasizing baptism as obedience to the gospel and entry into the Kingdom. The lesson explains baptism as essential to the new birth, an expression of genuine repentance and true faith, and the means by which believers are identified as God’s covenant people. It addresses immersion as the biblical mode of baptism, highlights the apostles’ serious treatment of baptism as a command, and affirms its public practice within the church. Finally, it presents water baptism as more than a symbol, teaching it as a spiritual work that buries the old life of sin and raises the believer to new life in Christ.