Previously, I wrote on what the Holy Spirit baptism was and when it happened. Essentially, the Holy Spirit baptism is what is called in Western Catholic Confirmation, and in the East Chrismation. However, among Baptists who concede its undeniable that Scripture teaches baptism saves (eg Mark 16:16, Acts 2:38, 1 Peter 3:21 etc.) they insist the baptism that saves is not water baptism but the dry baptism of the Holy Spirit which they typically claim comes at the moment you believe. While some might concede that the Holy Spirit in the book of Acts was not received until an Apostle appeared (eg Acts 8:16-19)
As evidence for the Holy Spirit baptism coming at the moment of belief being normative AFTER Acts they cite Ephesians:
That we should be to the praise of his glory, who first trusted in Christ. In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,--Ephesians 1:12-13 (KJV)
Noting that it says "after...ye believed, ye were seal with that holy Spirit..." First, this verse says the seal of the Spirit came AFTER believing, not simultaneous. Second and most importantly, the Ephesians received the Holy Spirit after they were water baptized and then received the laying on of hands. In fact, Acts tell us exactly this:
And it came to pass, that, while Apollos was at Corinth, Paul having passed through the upper coasts came to Ephesus: and finding certain disciples, He said unto them, Have ye received the Holy Ghost since ye believed? And they said unto him, We have not so much as heard whether there be any Holy Ghost. And he said unto them, Unto what then were ye baptized? And they said, Unto John's baptism. Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus. When they heard this, they were baptized in the name of the Lord Jesus. And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spake with tongues, and prophesied. And all the men were about twelve. --Acts 19:1-7
The book of Ephesians tends to use more abstract terms, while other letters like Colossians, Romans, Timothy use more concrete terms like baptism, laying on of hands. In fact, Ephesians 2 is about baptism but never uses the term but only uses terms like "saved by faith" when the corresponding chapter in Colossians 2:12-13 refers to this as "baptism." Paul does similar in Ephesians 1 when talking about receiving the Spirit.
Acts has the typical order as 1) believe 2) baptized with water 3) Holy Spirit baptism by laying hands. The exceptions to this order is in Acts 10 with the gentiles and Cornelius who received the Spirit by the preaching of the Apostle Peter. This was done to show the Jewish Christians God has accepted the gentiles. Even Acts 10 we see the order returning to normal in Acts 19.
Some will cite the Holy Spirit in the letters of the Corinthians in a similar manner as Ephesians 1:12-13, but before Paul came to Ephesus they were in Corinth in Acts 18, Acts 19 mentions Apollos stayed behind there. What indication is there they followed the new Baptist order where the Holy Spirit comes the moment you believe?
This issue with baptismal regeneration is just another instance of some Reformed and Baptists redefining terms. When Scripture mentions baptism saves, they redefine the word "baptism" when no clarification that the Holy Spirit baptism is referred to in order to fit their theology. They redefine the word "eis" meaning "for" in Acts 2:38 to avoid the obvious conclusion that "baptism is for the remission of sins" and is used in the same way as Matthew 26:28 "the blood of the new covenant being shed FOR THE REMISSION OF SIN." In fact, confessional Reformed that deny baptism regeneration will also redefine the Creed of Constantinople's reference in a similar manner, despite the conciliar Fathers confessing baptismal regeneration. They redefine "justified" in James 2:24 to mean vindicated, or "justified before men" despite James citing the exact same verse St Paul does in Romans 4. Not to mention the abuse given to the word "imputed" when the Bible speaks of justification!, or the word "tetelestai"--"it is finished" which they concocted off of since revised claims about receipts to concoct evidence for Penal Substitutionary Atonement. The solution at times is to appeal to fabricated, fictional definitions of words, or fanciful interpretations.