Is baptism a part of salvation?
Concerning the necessity of baptism for salvation, the Scriptures teach that it is as necessary as anything else that God commands us to do in order to be saved, forgiven. That is, we must believe in Jesus as the Son of God, repent of our sins, confess Him to be the Son of God and be baptized in order to be forgiven. I believe this because the Scriptures plainly teach it. Jesus authorized the apostles to baptize people for forgiveness of sins and that's exactly what they did.
MAT 28:18 And Jesus came up and spoke to them, saying, "All authority has been given to Me in heaven and on earth.
MAT 28:19 "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit,
MAT 28:20 teaching them to observe all that I commanded you; and lo, I am with you always, even to the end of the age. "
MAR 16:15 And He said to them, "Go into all the world and preach the gospel to all creation.
MAR 16:16 "He who has believed and has been baptized shall be saved; but he who has disbelieved shall be condemned.
ACT 2:36 "Therefore let all the house of Israel know for certain that God has made Him both Lord and Christ-- this Jesus whom you crucified."
ACT 2:37 Now when they heard this, they were pierced to the heart, and said to Peter and the rest of the apostles, "Brethren, what shall we do?"
ACT 2:38 And Peter said to them, "Repent, and let each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit.
The problem that many have is believing that somehow baptism is separated from the faith we are supposed to express toward Jesus. However, the Bible teaches that the believer who repents and confesses Jesus is expressing trust in the sacrifice and resurrection of Jesus when he is baptized.
ROM 6:1 What shall we say then? Are we to continue in sin that grace might increase?
ROM 6:2 May it never be! How shall we who died to sin still live in it?
ROM 6:3 Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death?
ROM 6:4 Therefore we have been buried with Him through baptism into death, in order that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life.
ROM 6:5 For if we have become united with Him in the likeness of His death, certainly we shall be also in the likeness of His resurrection,
ROM 6:6 knowing this, that our old self was crucified with Him, that our body of sin might be done away with, that we should no longer be slaves to sin;
ROM 6:7 for he who has died is freed from sin.
COL 2:11 and in Him you were also circumcised with a circumcision made without hands, in the removal of the body of the flesh by the circumcision of Christ;
COL 2:12 having been buried with Him in baptism, in which you were also raised up with Him through faith in the working of God, who raised Him from the dead.
COL 2:13 And when you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions,
Faith involves responding to God as He has directed so that we might benefit from the saving work that Jesus has accomplished for us by shedding His blood and entering into heaven on our behalf as High Priest before God.
Finally, the Scriptures teach that baptism is that turning point where our sins are washed away and we come into a relationship with Christ.
ACT 22:16 'And now why do you delay? Arise, and be baptized, and wash away your sins, calling on His name.'
GAL 3:26 For you are all sons of God through faith in Christ Jesus.
GAL 3:27 For all of you who were baptized into Christ have clothed yourselves with Christ.
GAL 3:28 There is neither Jew nor Greek, there is neither slave nor free man, there is neither male nor female; for you are all one in Christ Jesus.
GAL 3:29 And if you belong to Christ, then you are Abraham's offspring, heirs according to promise.
http://www.biblesearch.com/answers/salvation/baptism1.htm