You think the following verses really mean this?...You skipped verse 43 is why I hold to that contention because it opposes how you apply Acts 2:38 to mean.
43 To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins.
44 While Peter yet spake these words, the Holy Ghost fell on all them which heard the word.
45 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
46 For they heard them speak with tongues, and magnify God. Then answered Peter,
47 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
48 And he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days.
Since they got the Holy Spirit immediately afterwards for believing in Him is why water baptism isn't necessary for salvation for they were born again of the Spirit.
Water baptism is for believers to follow after they are born again, to identify themselves as disciples of Jesus Christ in being a follower of Him.
The like figure whereunto even baptism doth also NOT 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.
Or...
16 He that believeth and is NOT baptized shall be saved; but he that believeth not shall be damned.
Or....
38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ NOT for the remission of sins, and ye shall receive the gift of the Holy Ghost.