Peter cant preach what he does not know. So, if you want to talk about water in Acts 2, then be sure to realize that Paul was not an Apostle yet, and Jesus had not revealed "justification by faith" yet. So, Peter was preaching John's baptism or Mark 16:16 for the remission of sins, while also telling them to trust in Jesus. Later, as he understood "The Grace of God" as revealed to Paul, his "gospel" changes. So, if you believe that Peter, in Acts 2.... is preaching "Justification by Faith", as ONLY revealed to Paul many years later, then i'll let you continue in your "situation", while i continue in mine.