Why Repentance and Not Baptism?

“Then 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.” Acts 2:38

Regarding this verse, many suggest that repentance is the key to forgiveness and not baptism. I agree that repentance is absolutely essential for the remission of sins but what in Peter’s statement would suggest that baptism is not? When those listening to Peter’s sermon on the Day of Pentecost were pricked in their heart they said unto Peter and to the rest of the apostles in V37 “Men and brethren, what shall we do?” V38 Then 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.” Those asking this question believed that Jesus was the crucified and risen Messiah or else they would not have asked the question. That belief, however, was not enough as Peter gave them further instruction. They were instructed to repent and be baptized for the remission of their sins and the result of that would be that they would receive the gift of the Holy Ghost. Most have no problem with repentance in Acts 2:38 being for the remission of sins and neither do I, but why is there a problem with the baptism part?