I baptize you with water for repentance, but He who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire." John was making a clear distinction of status between himself and the One who was coming after him, i. e., Jesus. While John was performing an external rite with water, Jesus would do an internal work "with the Holy Spirit and fire."
Pentecostals take the reference as one thing, that "Holy Spirit" and "fire" are appositives, referring to their experiences of tongues, etc. Orthodox Protestants, on the other hand, consider the baptism with the Holy Spirit to be something that happens to every true believer when he is born again. I consider that understanding to be consistent with I Corinthians 12:13: "in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit" (see also John 7:39).
That phrase, "baptized with the Holy Spirit," occurs several times in the New Testament. We find it in Mark 1:8, John 1:33, Acts 1:5, 11:16, and 18:25. In none of these verse is it paired with "fire," even in the parallel verses in Mark 1:8 and John 1:33.
I think we must take that to mean that "with the Holy Spirit" and "with fire" are not different words for the same thing, but rather references to contrasting things. "Baptism with the Holy Spirit," as Paul indicates, is something that happens to every believer. Then, to whom does the contrasting "baptism with fire" apply?
On whom else does Jesus attribute a pouring out of fire? He mentions Sodom and Gomorrah (Luke 17:29), and unrepentant unbelievers (Matthew 25:41). These verses indicate that "fire" is not used for an extra-spiritual experience of the saved, but rather for judgment on the wicked (compare Mark 9:42-49).
This gives, I think, by analogy of the faith, what John was saying of Jesus: "I baptize you with water for repentance, but He who is coming after me will baptize you [believers] with the Holy Spirit and [you unbelievers with] fire." Note that "you" is plural, so he is addressing the whole audience, not anyone in particular. That is why he would have used an inclusive comment. To have spoken as the Pentecostals interpret him would have him to assume that all of his audience was - or would be - believers, which is obviously not the case.
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