Act 2:38 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.
Repent , for the forgiveness of sin
THEN be baptized
Two separate acts Repent and be forgiven and then be baptized for the Holy Spirit
There was the baptism of John for the repentance of sin in the Gospels which are actually Old testament
Thoose that had been baptized by john were baptized again
First, you say Peter made a mistake. Then when I call you out on that illogical statement, you go with the old restructuring of the sentence argument, saying that he was misunderstood. Apparently 3,000 + people misunderstood the Holy Spirit speaking through Peter on that day since they were baptized. And the Bible clearly says that those who were baptized that day were added to the church. In other words, they were saved. Just face the fact that you don't have a real answer for this verse.
The idea that repentance is tied to the remission of sins, and baptism is not, is a bogus one. The "and" in that passage between "Repent" and "be baptized", which as you must know is a conjunction, ties them together. The conjunction "and" never separates two things, always joins them. The Greek word here is "kai" and it has the meaning I just described. Even if you wanted to tie only one of the verbs to remission of sins, it would be baptism the way the sentence is structured. However, that is not the case since the Bible clearly teaches that repentance is necessary for salvation.