Pentecostal theology teaches the Baptism in the Holy Spirit (or Baptism with the Holy Spirit) is a definite experience, not identical with conversion (Acts 19:2). That is to say, it is both distinct from and subsequent to salvation (though it may occur immediately -Acts 10:44). While all believers are indwelt by the Holy Spirit, the Baptism with the Holy Spirit refers to the first time the believer is filled with the Holy Spirit (i.e.Acts 2:4). This does not mean however that that believer will be permanently filled with the Holy Spirit, but he is to seek to be filled when he is not (Eph. 5:18).
Glass of Water
Pentecostals often use the analogy of a glass with water.^[_citation\ needed_]^ The believer is the glass, and the water is the Holy Spirit. All believers have the Holy Spirit, the glass always has some water (as long as they are believers). Some believers have more water than others (have more of the power/influence of the H.S.) but are not completely filled with water. The believer who is filled with the H.S. is the glass that is completely filled with water (he is completely under the influence of the H.S., i.e. Acts 7:55, 13:9), and the first time this happens is called the Baptism of the Holy Spirit.
Pentecostals have traditionally believed that the Baptism in the Holy Spirit is physically evidenced by the supernatural gift of speaking in other tongues (glossolalia). That is, a person who is baptized with the H.S. will speak in tongues. A person may experience a good measure of the H.S., and yet not have been baptized in the H.S. Now, the better pentecostal theologians distance themselves from this viewpoint.
Pentecostal�s (and other�s) point to the close association of Biblical references to "Baptism with the Holy Spirit" and with “speaking in tongues". In the book of Acts, there are three specific references to individuals speaking in tongues: Acts 1:4, Acts 10:46 and Acts 19:6. Each of these instances of tongues-speaking is immediately subsequent to or contemporary with an experience of being "baptized with the Holy Spirit". The experience in Acts 1:1-4, which included tongues-speaking (see Acts 1:4), may be connected with the prediction by Jesus in Acts 1:5 that the disciples would be "baptized with the Holy Spirit not many days from now." This experience was referred to later in retrospect by Peter as well, as being "baptized with the Holy Spirit" (Acts 11:16). The description of Cornelius' household receiving the gospel from Peter and his companions in Acts 10:46, which included a reference to their "speaking in tongues", is later associated by Peter with the Pentecost experience of the disciples, relating that Cornelius and his friends and family were "baptized with the Holy Spirit" as the disciples had been at Pentecost (Acts 11:16). Acts 19:6, which includes reference to individuals in Ephesus "speaking in tongues", although not specifically using the term "baptized with the Holy Spirit", states that the "Holy Spirit came upon them".
1 Corinthians 12:13
1 Cor. 12:13 is the verse Cessationistsuse to show that the Baptism of the Holy Spirit occurs at conversion, regardless of experience. That is, all believers receive the baptism of the Holy Spirit when they believe since they were "baptized" "by one Spirit" into the body of Christ, whether they experience anything or not.
Regarding this, John Piper (who is not a pentecostal but a reformed noncessationist) says...
Now the positive thing I want to say about the moderate Pentecostal teaching (represented by the Bennets) is that it is right to stress the experiential reality of receiving the Spirit. When you read the New Testament honestly, you can't help but get the impression of a big difference from a lot of contemporary Christian experience. For them the Holy Spirit was a fact of experience... I think that being baptized with the Holy Spirit (the way Luke means it) is not the same as being born again or being united to Christ by the work of the Holy Spirit. In other words I don't think that what Paul is talking about in 1 Corinthians 12:13 is the same as what is happening here in Acts. Paul says, "For by one Spirit we were all baptized into one body—Jews or Greeks, slaves or free." The context shows that he is referring to a work of the sovereign Spirit who unites all believers to Christ. In another sermon he says,
Receiving the Spirit Is a Life-Changing Experience : This is why Paul can say in Acts 19:2 when he meets the confused disciples of John the Baptist, "Did you receive the Holy Spirit when you believed?" What would a contemporary Protestant evangelical say in response to that question? I think we would say something like, "I thought we automatically received the Holy Spirit when we believed. I don't understand how you can even ask the question." How could Paul ask that question? He could ask it, I think, because receiving the Holy Spirit is a real experience. There are marks of it in your life. And the best way to test the faith of these so-called disciples is to ask them about their experience of the Spirit.