The Lord Jesus instructed His disciples in the keeping of the sacrament of baptism, which was planned to be a blessing and assistance to them in their Christian life and ministry.
Many have defined baptism as an outward sign of an inward work that the Lord has done. The meaning of inward works or experiences are conveyed to the mind only by means of outward signs, figures or symbols. Therefore, if you do not understand the meaning of baptism you will only dimly understand its inward importance. Just as the Lord's Supper, or Communion, is a constant reminder of Christ's work of redemption, so baptism is a lifelong reminder of Christ's redeeming work in the life of a believer.