The Great Crowd only know the baptism of John, not the baptism of Christ.
From the Insight book:
Further understanding of the meaning of John’s baptism is gained by comparing various translations of Luke 3:3. John came “preaching baptism in symbol of repentance for forgiveness of sins” (NW); “baptism conditioned on repentance” (CB); “baptism whereby men repented, to have their sins forgiven” (Kx); “baptism in token of repentance for the forgiveness of sins” (NE); “Turn away from your sins and be baptized, and God will forgive your sins” (TEV). These renderings make plain that the baptism did not wash away their sins, but the repentance and changing of their ways did, and of this, baptism was a symbol.
The baptism performed by John was therefore not a special cleansing from God through his servant John, but a public demonstration and symbol of the individual’s repentance over his sins against the Law, which was to lead them to Christ. (Ga 3:24) John thereby prepared a people to “see the saving means of God.” (Lu 3:6) His work served to “get ready for Jehovah a prepared people.” (Lu 1:16, 17) Such a work had been prophesied by Isaiah and Malachi.—Isa 40:3-5; Mal 4:5, 6.
And this, regarding being baptized into Christ:
The faithful apostles of Jesus Christ were baptized in water by John’s baptism. (Joh 1:35-37; 4:1) But they had not yet been baptized with holy spirit when Jesus pointed out that they were also to be baptized in a symbolic baptism like his, a baptism into death. (Mr 10:39) So baptism into his death is something apart from water baptism. Paul expressed himself in his letter to the Christian congregation at Rome, saying: “Do you not know that all of us who were baptized into Christ Jesus were baptized into his death?”—Ro 6:3.
It is Jehovah God who is responsible for the performing of such baptism into Christ Jesus as well as baptism into his death. He anointed Jesus, making him the Christ or Anointed One. (Ac 10:38) Thus God baptized Jesus with the holy spirit in order that, through Jesus, his followers might thereafter be baptized with holy spirit. Therefore, those who become joint heirs with him, with heavenly hopes, have to be “baptized into Christ Jesus,” that is, into the Anointed Jesus who, at the time of his anointing, was also begotten to be a spiritual son of God. They thereby become united to him, their Head, and they become members of the congregation that is the body of Christ.—1Co 12:12, 13, 27; Col 1:18.
The course of these Christian followers who are baptized into Christ Jesus is a course of integrity-keeping under test from the time they are baptized into Christ, a daily facing of death and finally a death of integrity, as described by the apostle Paul when he explained to the Roman Christians: “Therefore we were buried with him through our baptism into his death, in order that, just as Christ was raised up from the dead through the glory of the Father, we also should likewise walk in a newness of life. For if we have become united with him in the likeness of his death, we shall certainly also be united with him in the likeness of his resurrection.”—Ro 6:4, 5; 1Co 15:31-49.
Clarifying the matter still further, Paul, in writing to the congregation at Philippi, described his own course as “a sharing in [Christ’s] sufferings, submitting myself to a death like his, to see if I may by any means attain to the earlier resurrection from the dead.” (Php 3:10, 11) Only the Almighty God the heavenly Father, who is the Baptizer of those who are baptized in union with Jesus Christ and into his death, can complete the baptism. This He does through Christ by raising them up out of death to be united with Jesus Christ in the likeness of his resurrection, which is to heavenly, immortal life.—1Co 15:53, 54.