He came into all the region around the Jordan, preaching the baptism of repentance for remission of sins.
Baptism of repentance unto the remission of sins ... This baptism was a new rite, "not founded on the immersions of the old dispensation, but a divinely appointed act, peculiar to Christianity, and first introduced by John."[9] It is one of the seven baptisms mentioned in the New Testament.[10] It consisted of the immersion of the penitent in water by the administrator, requiring John to preach where there was "much water" (John 3:23); and, coupled with repentance, it was "unto the remission of sins."  John's baptism was, in fact, "God's baptism"; and those who rejected it rejected God (Luke 7:30).  It was the only baptism ever submitted to by the apostles of Christ (Paul excepted) and was the only baptism in force until Pentecost.  Those baptized by John and who followed on to receive the Spirit of Christ experienced the new birth, being born of water and of the Spirit, as Jesus commanded (John 3:1-5).  Significantly, the new birth, which requires a birth of water (baptism) and a birth of the Spirit (receiving the Holy Spirit as promised in  Acts 2:38), could not be experienced until after Jesus was risen from the dead (John 7:39).  From this it is clear that "the remission of sins" was a blessing which John promised prospectively, the actuality of it being necessarily deferred until Pentecost.