Is baptism a requirement for salvation?

No, it is not a requirement for salvation today according to the Bible (rightly divided)!

The water baptism is a ministry to Israel and according to Mark 1:4; Acts 2:38; and I Corinthians 1:17,18; it was required of them “For the Remission Of Sins.” With the salvation and commissioning of Paul as the Apostle of the Gentiles (Romans 11:13) God not only postponed his dealings with Israel (until he resumes with the pouring out of His wrath) but in His grace turned to us Gentiles and revealed through Paul “The preaching of the Cross.” No one preached the “good news” of the cross until Paul came on the scene in the Bible. Today we are saved by grace through faith in the finished work of the Lord Jesus in His death, burial and resurrection as the full, complete payment for our sins.