You're confusing John's baptism with Christ's baptism. John's water baptism was unto repentance; water baptism in the name of Jesus is unto forgiveness of sins. Peter and the apostles were given the authority to authorize it.
I'm glad someone knows baptism is in the name of Jesus,for Luke said baptism is to be done in Jesus' name,for Jesus is the name of the Father,Son,and Holy Ghost,which the Father in the Old Testament said He would reveal a new name to the Jews,and Jesus said He came in His Father's name,and Hebrews chapter 1 says,that the Son inherited the name from the Father,and the Spirit comes in the name of Jesus,which in the book of Acts,Jews,Gentiles,and Samaritans were all baptized in the name of Jesus,in which some were baptized unto John's baptism,but had to be baptized in to Jesus' name,in which there is no other name under heaven whereby we are saved,which Father,Son,and Holy Ghost,are titles,not names,and everything we do in word,and deed,do all in the name of Jesus.
1Pe 3:18 For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
1Pe 3:19 By which also he went and preached unto the spirits in prison;
1Pe 3:20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
1Pe 3:21 The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ:
1Pe 3:22 Who is gone into heaven, and is on the right hand of God; angels and authorities and powers being made subject unto him.
Rom 6:3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
Rom 6:4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
Rom 6:5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
Rom 6:6 Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
Baptism is necessary for salvation,for we must identify with the man Christ Jesus,who died,was buried,and resurrected,by repenting of our sins,being water baptized,and receiving the Spirit.