The New Testament uses several images to describe what baptism means.
First, baptism symbolizes a spiritual union with Christ (Rom. 6:3-8), involving participation in His suffering, death, and resurrection, as well as the renunciation of one’s former lifestyle. In this way, baptism is linked with repentance and the forgiveness of sin (Acts 2:38); the new birth and reception of the Spirit (1 Cor. 12:13); and, consequently, entrance into the church (Acts 2:41, 47).
Baptism symbolizes a covenantal and spiritual relationship with God through Christ (Col. 2:11-12). Baptism represents what circumcision represented in the Old Testament. And, too, baptism symbolizes a transfer of loyalties, one that places a person into a community that is consecrated to the service of Christ. The reception of the Spirit in baptism enables believers to serve the church and work for the salvation of those who are not yet of the faith (Acts 1:5, 8).
Several years ago the Joint Committee of the Church of England on Baptism, Confirmation, and Holy Communion made an impressive admission. The statement said that ‘the recipients of Baptism were normally adults and not infants; and it must be admitted that there is no conclusive evidence in the New Testament for the Baptism of infants.”-Baptism and Confirmation Today (London: SCM, 1955), p. 34, quoted by Millard J. Erickson, Christian Theology (Mich.: Baker Book House, 1988), p. 1102. The meaning of baptism precludes infants as legitimate candidates, because biblical baptism requires faith and repentance on the part of the participants. Also, the idea of the role of the Word of God in the development of faith (Rom. 10:17) indicates that repentance must be coupled with biblical and spiritual instruction. These elements are necessary in order for candidates to bring forth ‘fruits worthy of repentance’ (Luke 3:8) as evidence of their relationship with Christ.
The nature of baptism helps us to understand the difference between an ordinance and a sacrament. Baptism, according to those who see it as a sacrament, is the means that brings about the transformation in a person from spiritual death to life. In this understanding, the age of the person doesn’t matter, because it’s all a supernatural event anyway. On the other hand, baptism as an ordinance is an indication or symbol of an internal change (a supernatural event) that has already occurred in the life of the believer by way of his or her experience with Jesus. In this view, candidates for baptism ought to have already experienced faith in Christ; therefore, the question of who is baptized, and when, becomes very important.
If you have been baptized, think back upon the experience. When you understand what it means, why (in a sense) do we need to be ‘baptized’ every day? How can this be accomplished?