Peter was wrong in Acts 2:38?
That is not a wrong or right, situation.
That is an apostle who is been given a specific gift of The Spirit and was not water baptized to get it.
He is filled with the Spirit, and was not water baptized to get it.
So what does that mean?
It means that all water cults are lying to you.
That is what Act 2:38 is showing you.
Also, Peter is teaching and preaching, what he understands at that time...
Thats all it is..
Later, this apostle does not preach or teach John the Baptist's OT message , but in Acts 2, He does.
Much later, in 2nd Peter, He is proclaiming Paul's letters as equal to the Torah, at that time, while he is reading them.
And he is right, as later... Paul's letters created most of the New Testament and Doctrine for the Church.