God chose immersion in water for the mode of baptism because it is a prevailing method of showing us that our sins must be forgiven. The ordinance of baptism was designed by God and uses the inspired words to fit a symbol. Immersion is an object lesson that is a visual analogy of our spiritual reality.
Baptism is a Declaration of Personalized Truth
God designed baptism to be a means by which believers could publicly declare their allegiance to Him. Clearly and unambiguously throughout the New Testament, believer’s baptism is a portrait of the union of a believer with Christ. The persons to whom the commission of Christ in Matthew 28:19 is directed are those who have become believers in Jesus. “It is impossible that a command to baptize believers, can be extended to include any but believers.” Heaven and earth will pass away before the duty of every believer to declare their personalization of the truths of the Gospel in the waters of baptism has been vanquished.
Baptism is a Burial Picture
Romans 6, Galatians 2, Galatians 3, Colossians 2 all clearly teach that baptism is a picture of the believers union with Christ in his death, burial and resurrection. In recent times there has been a debate over whether or not the picture of burial and resurrection is warranted in these texts. Galatians 3:27 in particular seems to have as much warrant to attach the image of putting on clothing as it does the image of death and resurrection. “For as many of you as have been baptized into Christ have put on Christ.” This seems to indicate Christ’s righteousness and the ‘clothing’ of a new life. It has been suggested that Paul may have been describing putting on a dry robe after emerging from the waters of baptism. This is a logical answer but does not silence all the critics.
However, Romans 6 and Colossians 2 cannot be explained away like Galatians 2. The symbolism in these two passages is much too strong to be set aside. The picture that Paul is drawing here is so obvious that even some paedo-baptists have to agree that Paul is drawing a comparison between baptism and Christ’s burial and resurrection.
Once a person has put his faith in Christ he has been placed into union with Christ. In that way he has been immersed in Christ. Therefore, the believer is one with Christ in his death, burial, and resurrection. Romans 6 makes this very clear. “Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.” The waters of baptism symbolize this union. Immersion into the water is the outward sign of the believers inward union with Christ.
Baptism is one of the two ordinances God has given to the church (along with the Lord’s supper). At the heart of the church’s expression of its allegiance to Christ are these two ordinances. Baptism is thus a solemn act that the church has an obligation to perform. Its significance is unmistakably clear. It is important that the person being baptized has received Christ, renounced His former sinful life, and is willing to publicly proclaim his new found faith. Practicing anything other than believer’s baptism leads to ritualism, false-security, and great confusion.
 Carson, 169-170.
 Masters, 21.
Posted by Caleb