John the Baptist had closely interrelated repentance, water baptism, and the kingdom being at hand—an event about to happen. Jesus continued this message. When Jesus commissioned His disciples to continue His work after His departure, He included the ministry of water baptism as an integral part of their ministry. The Bible gives us several reasons for the command requiring obedience to the gospel in terms of water baptism. 

Water baptism is essential to the new birth. 

Regeneration or the new birth is not something we can do for ourselves. It must be done for us by the Lord. This spiritual awakening results in our entering into a whole new dimension of life: the kingdom of God. Jesus first explained the necessity of such a thorough supernatural change to the Jewish teacher, Nicodemus. Jesus answered and said unto him, Verily, verily, I say unto thee. Except a man be born again, he cannot see the kingdom of God…. Jesus answered, Verily, verily, I say unto thee. Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God (John 3: 3, 5). 

Water baptism is an expression of genuine repentance. 

In the preaching of John, Jesus, and the disciples, water baptism was taught as directly related to repentance. As soon as people were convicted of their sin and realized their need of God’s saving work, they were told both how to believe and how to obey the gospel. The fruit of their change of mind and heart would be seen in their submission to water baptism. And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem (Luke 24: 47). Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost (Matthew 28: 19). 

Water baptism is an expression of true faith. 

When we truly believe something and are deeply persuaded it is true, we give ourselves wholly to it. Water baptism was an important step of commitment required of all who would enter the kingdom of God. Through water baptism, the believer renounced his former allegiance to the world and its system, and declared himself subject to the Lordship of Christ. Go ye into all the world, and preach the gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned (Mark 16: 15, 16). 

Water baptism marks us as a part of God’s people. 

The kingdom of God involves more than obedience to a new king. It also includes membership in a whole new spiritual nation, God’s kingdom of kings and priests. God’s old Covenant nation was marked as His possession through a covenant of blood and of circumcision. The blood of animals was shed for the covering of sin. The foreskin of each male was circumcised on the eighth day as a token of membership in God’s covenant nation. Spiritual Israel—God’s New Covenant people—also has an initiatory rite: the circumcision of heart received in water baptism. No one was made a part of the local church in the New Testament until he had submitted to water baptism. But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvelous light: Which in time past were not a people, but are now the people of God … (1 Peter 2: 9, 10).