Christ told his apostles to preach the gospel to all the world. and those that "believe and are baptized shall be saved, and those that believe not shall be damned." Elsewhere he said that unless a person is "born of water" he cannot enter into the kingdom of God. Some feel this may refer to natural birth. To resolve this argument, God has reaffirmed in our times His commandment to be baptized.
Baptism is not meant to be just a technicality, but a life-changing event. The highest levels of heaven are filled with those who have given their lives to Christ, and who seek every moment to live as He lives, to love as He loves, to be as He is. A baptism asserting one's allegiance to and desires to follow Christ is then not a technicality, but rather an essential beginning step on that path.