It need hardly be said that the baptism of John was not Christian baptism in any wise. It was unto repentance for remission of sins”— those who were baptized looked for a living Messiah to come, who would baptize with the Holy Spirit.
Christian baptism is “unto death.” Baptism is always “unto” (εις) something — see Romans 6 and for “into” read “unto” or “to.” Christian baptism and John’s baptism are put in contrast in Acts 19:1-5 as totally distinct.
Those who were baptized of John were professedly coming in under the dealings of God in sovereign mercy, and where grace called them. It was no use now, as he told them, to say that they had Abraham to their father; this did not entitle them to the promises. They knew what it involved — that is, the meaning of accepting the baptism of John. It was the renunciation of everything to which they clung as men after the flesh. Hence the Pharisees sent priests and Levites from Jerusalem to ask him, “Who art thou?” “Why baptizest thou then, if thou be not that Christ nor Elias, neither that prophet?” Sensible of what baptism involved, as throwing them out of everything they prized after the flesh or entitled to as children of Abraham, they would not accept what was to them so intolerable, unless from someone such as Christ, Elias, or that prophet, who would be entitled to change the whole constitution. The people and the publicans who accepted it, “justified God, being baptized with the baptism of John” (Luke 7:29, etc.). They recognized His justice in condemning them, and His grace in calling to repentance such as they, while “the Pharisees and Lawyers rejected the counsel of God against themselves, not being baptized of Him.” They refused to surrender what they prized after the flesh, and come in under God’s dealings in grace on the level of those they despised. If Johns baptism had been received by the nations, Christ would not (to speak as a man) have been rejected and put to death, and consequently there would have been no Christian baptism at all.