Tongues as a New Testament entity first burst on the scene in Acts 2. The key verse in this chapter is verse 16, "...THIS IS THAT which was spoken by the prophet Joel."

      What is "this" and "that"?

      Verse 17 is a quote of Joel 2:28 and reveals what "this" and "that" are. "I will pour out my Spirit upon all flesh; and your sons and daughters shall PROPHESY." In quoting Joel, Peter was telling the crowd that THIS thing (called tongues by the New Testament writers) was THAT same thing called "prophesy" by the Old Testament writers!

      A "tongues = prophesy" principle was the main point Peter was trying to bring out in quoting Joel. This is confirmed by Peter adding his own words, "and they shall prophesy," in quoting Joel 2:29.

      Those Jews Peter was addressing were quite familiar with the Old Testament phenomenon of the Holy Ghost falling upon select individuals and causing them to SPEAK -- even speak as if they were out of control (I Samuel 19:20-24). These Jews were also familiar with God's promise in Joel that one day the Spirit of God would not just fill certain people but would be available to everyone -- all flesh, male and female.

      When Peter simply quoted Joel, the crowd realized that the disciples had been filled with the Holy Ghost and were not a bunch of rowdy drunks.

      What occurred in Acts 2:4 when "they were all filled with the Holy Ghost, and began to speak" was not some "new" thing. It was the same Holy Ghost experience many an Old Testament person had already experienced. This was that which the elders in Numbers 11:24-29 had experienced. This is that which David, the prophets, and Saul's messengers had experienced at Ramah (I Sam. 19:18-24).

      This was that which Elisabeth experienced when she was "filled with the Holy Ghost: and she spake" (Luke 1:41-42)...when Zacharias "was filled with the Holy Ghost, and prophesied" (Luke 1: 67)...that the 12 men at Ephesus experienced when "the Holy Ghost came on them; and they spake with tongues, AND prophesied" (Acts 19:6).

      Acts 2 records the first use of a new term (tongues) for an old phenomenon -- speaking by the unction of the Holy Ghost. Thereafter this would usually be called "tongues" rather than "prophecy," but the experience remained the same. This terminology change in the New Testament is similar to the change from "seer" to "prophet" in the Old Testament (I Samuel 9:9).

      Though nothing new began at Pentecost, something wonderful did happen. Before that day, being endued with power from the Holy Ghost for the supernatural work of God was available to only a few select Jews. That Pentecost Moses' wish (Num. 11:29) and Joel's prophecy (Joel 2:28) began to be fulfilled -- the PROMISE of the power of the Holy Ghost for ALL people.

      In Acts 1:4-5 Jesus tells His disciples, who were already "saved" by faith in Him, that they would receive "the promise" to "be baptized with the Holy Ghost." When the day of Pentecost came, all the disciples, both men and women, received God's promised baptism with the Holy Ghost!

      The Jews in the crowd that day were also aware of this great promise that one day they could all be endued with the same Holy Ghost power as Moses, Joshua, and David.

      Those Jews who saw and heard the disciples that day thought they might be drunk until Peter told the crowd "this was that." When Peter said this, they didn't leave but stayed to listen to his sermon recorded in Acts 2:22-36.

      After gaining their attention, he explained how the disciples had received the promised Holy Ghost. Peter told them Jesus was indeed the Messiah, that He had been raised from the dead, that because of this Jesus had "received of the Father the promise of the Holy Ghost," and that Jesus "hath shed forth this, which ye now see and hear" (Acts 2:33).

      Being pricked in their hearts by Peter's message the crowd asked what they should do. Peter told them to repent and turn to God through belief in Jesus as the Christ (Acts 2:38, see also Acts 3:19). Peter also told them to be baptized in water in Jesus' name as a witness of their conversion to Jesus as their resurrected Lord.

      Peter then added that if they would do this they would "receive the [promised] gift of the Holy Ghost [baptism]. For the promise [of the Holy Ghost] is unto you, and to your children, and to all that are afar off [us today], even as many as the Lord our God shall call (Acts 2:39). See also Ephesians 1:13.

      It is obvious that the prevailing theme of Acts 1:4 - 2:39 is the baptism of the Holy Spirit as a fulfillment of Joel 2:28-29! It is also obvious that "this" of the New Testament is the same thing as "that" of the Old. Further, the term "promise" is used exclusively throughout this passage in reference to the baptism with the Holy Ghost.

      In talking about the baptism with the Holy Ghost in Acts 2:33, Peter stated that what the crowd NOW SAW AND HEARD (the disciples carrying on and speaking in tongues in the background) was an effect of the Holy Ghost baptism. Thus, Acts 2:39 can only be taken as an explicit statement that the Old Testament experience of being baptized with the Holy Ghost is available to all believers for the rest of time! (John 7:38-39, Mark 16:17).