Peter spoke of it so why do you deny it? Is Paul the only one you listen to and believe in? What happened to Christ? What church teaches that?
In the water-and-Spirit rebirth that takes place at baptism, the repentant sinner is transformed from a state of sin to the state of grace. Peter mentioned this transformation from sin to grace when he exhorted people to “be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit” (Acts 2:38).
http://www.catholic.com/library/Are_Catholics_Born_Again.asp
Acts 2:38
King James Version (KJV)
38Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
Peter preached at Pentecost that same message: "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins...(Acts 2:38).
Paul was saved in Acts 9 and was baptized. (Acts 9:18).
Hebrews 9:16,17: "For where a testament is, there must also of necessity be the death of the testator. For a testament if of force AFTER men are dead; otherwise it is of no strength at all while the testator liveth."
Christ's blood could not be given for the remission of sins during His time on earth because HE HAD NOT DIED FOR OUR SINS YET. Peter and the 11 did not know He was going to die FOR OUR SINS. Read Peter's sermon on the day of Pentecost. Does he share the good news that Christ died for our sins? Does he excitedly tell everyone that the blood of Christ is for the remission of sins? NO. Because he did not know that. Read Acts 2 again and again if you have to. It's NOT good news Peter is spreading.
Now to Paul. He is saved in Acts 9 and is baptized within 3 days of his first blinding vision from the risen Christ. Of COURSE he is baptized. It is in keeping with the Kingdom gospel for the Jews.
In Galatians 2:7, Paul says this gospel of the uncircumcision-Grace_ was committed unto him. Are they the same gospel? Peter's gospel included a command to preach and baptize, Paul's gospel does not. "For Christ sent me NOT TO BAPTIZE, but to preach the gospel..."1 Cor. 1:17.
But didn't Paul baptize some/ Yes, but he says "I THANK GOD that I baptized none of you, but Crispus and Gaius...the household of Stephanas...I know NOT whither I baptized any other."
His gospel OBVIOUSLY could NOT have contained the command to baptize, otherwise he would not have thanked God that he baptized so few.
It is very clear in Scripture that when the Dispensation of Grace began with the setting aside of Israel, Acts 28, water baptism, a Jewish ordinance, was set aside too. Baptism was a washing or a cleansing, something done by man for man's temporal cleansing. After the Dispensation of Grace began, Paul no longer preached, practiced, or performed things that were Jewish in character.
He preached the Grace of God. The Cross. Where the blood of Christ cleanses us from all sin. Something that could not have been preached before the death of the testator (Jesus Christ) and something that was kept secret until revealed to the Apostle Paul by direct revelations of Jesus Christ. The preaching of the cross is the shedding of Christ's blood for the remission of our sins. Not water.