From a forthcoming publication on the Holy Spirit
Baptism of the Holy Spirit is the moment in which the Holy Spirit takes up residence in believers; it is the receiving of the gift of the indwelling of the Holy Spirit. Spirit baptism is the fulfillment of God’s promise to make the human heart his home. It is the restoration of the divine presence that was lost at the fall in Genesis 3. The restoration of the divine presence is therapeutic to the corrupted and diseased human nature. The healing that it brings restores the holy-love character attributes to humanity that God always intended to share with his image-bearers. In other words, the baptism of the Holy Spirit makes people fully human; Spirit baptism makes people look like Jesus.
Old Testament promises of Spirit baptism
The Old Testament prophets predicted Spirit baptism. Jeremiah describes the restoration and renewal of the human nature that will come with this new covenant as the law of God being written on the hearts of his people:
Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Juda, not like the covenant that I made with their faithers…For this is the covenant hat I will make with the house of Israel after those days, declares the Lord: I will put my law within them, and. Will write it on their hearts. And I will be their God, and they shall be my people.Jer. 31:31–32a, 33; italics added
The law of God is a picture of who God is. His holy love is embedded in his commands for his image bearers. For his law to be transcribed on hearts is a metaphor meaning that God’s people will be the embodiment of his holy love; they will bearers of his image as he always intended.
Ezekiel, in the tradition of David in Psalm 51:10–11, describes this same dynamic as God giving his people a new heart and a new Spirit. He says:
I will take you from the nations and gather you from all the countries and bring you into your own land. I will sprinkle clean water on you, and you shall be clean from all your uncleannesses, and from all your idols I will cleanse you. And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in my statutes and be careful to obey my rules. You shall dwell in the land that I gave to your fathers, and you shall be my people, and I will be your God.Ezek. 36:24–28; emphasis added
Daniel Block helpfully points out that:
[the heart] represent the person’s internal locus of emotion, will, and thought. Like Jesus, centuries later (Matt. 15:17–20), Ezekiel recognized the problem of rebellion and sin against Yahweh to be more deeply ingrained than mere external acts. Ezekiel concretizes the metaphor by describing the heart as stone, which speaks of coldness, insensitivity, incorrigibility, and even lifelessness (cf. 1 Sam. 25:37).Daniel I. Block
The new Spirit that God will give Israel in this new covenant will be different than the heart in two respects, however. First, with the Spirit, God specifies that he will put it within believers. Second, it is specified that this new spirit will be “my [Yahweh’s] Spirit.” In sum, this new heart and new spirit will create a new humanity that will be faithful to the divine-image-bearing vocation.
The prophet Joel also foretells of the pouring out of the Spirit. He says:
And it shall come to pass afterward, that I will pour out my Spirit on all flesh; your sons and your daughters shall prophesy, your old men shall dream dreams, and your young men shall see visions. Even on the male and female servants in those days I will pour out my Spirit.Joel 2:28–29
Two noteworthy things here. First, the prophet emphasizes that the Spirit of Yahweh will be poured out on all flesh, which is distinct from the norms of first covenant. Second, and in harmony with Ezekiel, the Spirit that will be poured out is the Spirit of Yahweh himself.
This new Spirit-covenant would accomplish what the Mosaic law could not accomplish: a transformation of human nature. The Mosaic law made provision for the external cleansing of sin guilt. The new covenant would make provision for an internal cleansing.
Jesus and John the Baptist promise Spirit baptism
John the Baptist explained that while he baptized with water, Jesus would baptize with the Holy Spirit and fire (Matt. 3:11). Even Jesus himself taught that he would pour out the Holy Spirit on his followers (Jn. 14:15–17). The disciples were often either utterly surprised by or confused at what Jesus taught them, including the need for his substitutionary death (Matt. 16:22). The baptism of the Holy Spirit, however, was never questioned by the disciples. They understood and even expected this teaching from Jesus because of the promises of the Old Testament prophets.
Promises fulfilled at Pentecost
In his sermon on the day of Pentecost, Peter explains that this promise of the Old Testament prophets, John the Baptist, and Jesus was fulfilled at Pentecost. While many were confused at what exactly was happening at the Pentecost event, Peter gave an explanation. He says in Acts 2:32–33:
This Jesus God raised up, and of that we all are witnesses. Being therefore exalted at the right hand of God and having received from the Father the promise of the Holy Spirit, he has poured out this that you yourselves are seeing and hearing.
Having been a part of the last supper in which Jesus describes the wine as the wine of the new covenant, Peter understands and therefore explains that the Old Testament promises of a new Spirit-covenant are being fulfilled on the day of Pentecost.
Is Spirit Baptism new birth regeneration, or a second work of grace?
When Holy Spirit baptism occurs is debated across various traditions. Most traditions affirm that Baptism of the Holy Spirit is simultaneous with new birth (hence the language of being “born of the Spirit” (Jn. 3:5)) that results from justifying faith. Other traditions posit that Spirit baptism is a “second work of grace” that is subsequent to regeneration and the result of the Christian’s response to a deeper work of the Holy Spirit.
While both views find support in Scripture, most agree that the expected norm of the apostles in various scenarios in the book of Acts is for Spirit baptism to occur in the moment of conversion as a “conversion-initiation” and that accounts of a Spirit baptism occurring after justifying faith are abnormal.
One of the questions that remains is concerning the repeatability of those abnormal scenarios. The Samaritans in Acts 8:14–17, for example, had not received the Spirit because they were not taught about the Spirit from the start. Could that happen again in contemporary situations, or was that a one-off anomaly? While the disciples’ Spirit baptism at Pentecost occurred subsequently to their justifying faith in Jesus, it is easier to see how their situation was a unique, unrepeatable scenario (i.e., having lived through the historical events that gave birth to the church). That the case of the Samaritans would be a one-off situation is not as obvious. It seems feasible that while Spirit baptism occurring at the time of justifying faith could be the conversation norm described in the Scriptures, it seems there could be scenarios in which a lack of teaching of the full gospel could result in the necessity of Spirit baptism after conversion.
Nonetheless, the Wesleyan view of Spirit baptism, I believe, is helpful here. Baptism in the Holy Spirit from a Wesleyan perspective begins with Wesley’s understanding of the sin nature as an inheritance of an infirmity due to the loss of the divine presence (i.e., Holy Spirit) at the fall. The work of Jesus, which is not just to forgive but to restore, gives back to humanity what was lost.
Against this understanding of the human condition and its causes, the new birth is understood as the initial baptism in the Holy Spirit, the moment that the individual receives the gift of the Holy Spirit to recreate human life (Jn. 3:1–8). The emphasis here is that Jesus did not just die to forgive sins, but that he came also to restore. The restoration of the divine presence via the Holy Spirit then sets the Christian on a trajectory to experience a fullness of this baptism, which is a subsequent matter. Experiencing the fullness of the Spirit baptism is subsequent because the formation into desiring the fullness of the Spirit is important for personal responsiveness to God and a personal yielding to more of God’s work in the life of the believer.
There is a clear distinction, then between the recreating gift of the Holy Spirit in the new birth and the subsequent encounter in the life of discipleship where one’s life is consciously fully yielded to the transforming presence and lordship of the Holy Spirit. This is a gradual dying to self, by the empowerment of the Holy Spirit, which enables the believer to experience all the Spirit’s fullness.
This view harmonizes well with John Stott’s statement that, “we need to seek ever more of the Holy Spirit’s fullness, by repentance, faith and obedience, and also to keep sowing to the Spirit so that his fruit may grow and ripen in our character.”
 Daniel I. Block, The Book of Ezekiel, Chapters 25–48, The New International Commentary on the Old Testament (Grand Rapids: Eerdmans, 1998), 355.
 For a survey of views of the various traditions along with exegetical evaluation of those views, see James D. G. Dunn, Baptism in the Holy Spirit: A Re-Examination of the New Testament Teaching on the Gift of the Spirit in Relation to Pentecostalism Today, Second Edition. (London: SCM Press, 2010), John R. W. Stott, Baptism and Fullness: The Work of the Holy Spirit Today, Second Edition. (England: Inter-Varsity Press, 1975), and Allison and Köstenberger, The Holy Spirit, 383–395.
 The phrase “conversion-initiation” is from Dunn’s Baptism in the Holy Spirit.
 John R. W. Stott, Baptism and Fullness: The Work of the Holy Spirit Today, Second edition. (England: Inter-Varsity Press, 1975), 118.