The like figure whereunto baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God), by the resurrection of Jesus Christ.
This Scripture teaches us the importance of baptism and its proper subjects and mode. If one were to say that baptism is not important, he would be ignoring the plain command of Christ Who told His disciples to:
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)
Concerning its proper subjects and mode, the ceremony of baptism is not some secret or mysterious thing which requires complicated Biblical interpretation to understand; it is a very simple matter. In the Scripture above, it is called "the answer of a good conscience toward God." This reveals its proper subjects. The word translated "answer" refers to the answer given by one accused in court. The judge says, "How do you plead?" The accused who has a good conscience in the matter pleads "Not guilty." Baptism is a symbolic plea of "Not guilty," made by a sinner whose conscience is clear because His sins have been washed away by Christ. In order to make such a plea, one must understand the charges against him and how it is that he is made "not guilty," of those charges. Therefore, it is not suitable that infants be baptized, for they know neither their sin nor the means by which it can be removed.
The proper form of baptism is revealed in the manner by which sinners are made "not guilty." Sinners are made guiltless before God by means of a union with Christ in His death and resurrection; as Paul wrote, "I am crucified with Christ..." When Christ died and rose again, so did all who were in Him. Therefore, in Christ, they have paid for their sins and worked a perfect righteousness; their conscience is clear! Neither sprinkling nor pouring can picture this connection between Christ and His own; only an immersion. Sprinkling can no more be counted baptism than throwing a couple of handfuls of dirt on a corpse can be counted burial.