The functional creed for many Christians as Gordon Fee points out, could be stated something like this, “I believe in God the Father; I believe in Jesus Christ, God’s Son; but I wonder about the Holy Ghost.”

My religious upbringing was full of concern about heretics who taught that the Holy Spirit works “separate and apart from the Word of God” or that the Spirit literally indwells a Christian. How foreign that thinly disguised deism was from the Spirit-drenched reflections of the first-century Christ-followers.

The New Testament never develops a carefully prepared doctrine of the Spirit. However, its pages are filled with life-changing experiences of the early Christians that the God who had been present among them in Jesus Christ was still present in his Holy Spirit. They knew they had received the gospel message with joy inspired by the Holy Spirit (1 Thess. 4:8). They understood that they, the people of God, had become the temple in whom God through his Spirit dwells (1 Cor. 3:16-17). They recognized that only through the Spirit’s power were they able to live holy lives commensurate with their calling (1 Thess. 4:3-8).

Life apart from the presence and work of the Spirit was unimaginable. As Paul put it, “If anyone does not have the Spirit of Christ, he does not belong to Christ” (Rom. 8:9). Before his conversion, the apostle saw the world clearly divided into two groups: Jews and Gentiles. After receiving God’s grace, he saw humanity separated between those “in Christ” (which to him meant those with the Spirit) and those not in Christ (and therefore, without the Spirit).

So common was their experience of God’s Spirit that Paul could ask the Galatians, “Did you receive the Spirit by observing the law, or by believing what you heard?” (Gal 3:2). The argument he constructs in Galatians 3 stands or falls on this, their recognition that the Spirit had come powerfully into their lives at conversion and had continued to work in them to produce the character of Christ.

No New Testament writer set out to develop a formula for the Trinity, yet Trinitarian language abounds, for that was the early church’s experience in salvation. The one God had entered the world through his Son, Jesus Christ. And when that Son “left,” he still remained through “another Counselor” (John 14:16 – which implies that Christ, too, had been their Comforter or Counselor).

The benediction at the end of 2 Corinthians is typical. It doesn’t attempt to argue the case for a Trinitarian understanding of God, but it uses Trinitarian language to describe their experience, “May the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with you all” (2 Cor. 13:14). The Christians had experienced the love of God (which had been poured into their hearts by the Holy Spirit, Rom. 5:5), the grace of their Lord which gave expression to the Father’s love, and the participation in the Spirit which made that love and grace present in the church.

In their encounter with the gospel, they learned what the people of Israel had not known about their one God, that he existed in eternal relationship as God the Father, God the Son, and God the Spirit.

The prophets of Israel had looked forward to a day when God would pour out his Spirit. Through the preaching of Ezekiel, for example, God had said:

I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws…I will put my Spirit in you and you will live, and I will settle you in your own land (Ezek. 36:26-7; 37:14).

Luke, who was concerned to show that such promises to God’s people had indeed been fulfilled (Luke 1:1), reports that John the Baptist told the crowd around him that while he was baptizing in water, Jesus would baptize them with the Holy Spirit and with fire (3:16). Shortly before his ascension, Jesus told his followers to stay in Jerusalem and “wait for the gift my Father promised, which you have heard me speak about. For John baptized with water, but in a few days you will be baptized with the Holy Spirit.” (Acts 1:4-5).

On Pentecost, this promise was fulfilled. The disciples, hearing the howling of a violent wind and seeing what looked like tongues of fire, were filled with the Spirit (Acts 2:1-4). Peter explained that God’s people were experiencing the fulfillment of Joel’s prophecy:

In the last days, God says,
I will pour out my Spirit on all people.
Your sons and daughters will prophesy,
your young men will see visions,
your old men will dream dreams.
Even on my servants, both men and women,
I will pour out my Spirit in those days,
and they will prophesy.
Joel 2:28ff; Acts 2:17-18

But was this gift of God’s Spirit only for a few leaders? No! Peter told those who were listening that they too, upon repentance and baptism, would receive this gift (2:38).

Various groups have taught that the baptism in the Holy Spirit is a gift that comes to some Christians at a later point in their spiritual journey. But the New Testament writers considered it the normal experience for all believers at their conversion. Because of their common experience of baptism in water and in the Spirit, Paul could argue for Christian unity by saying, “For in one Spirit we were all baptized into one body – Jews or Greeks, slave or free – and we were all made to drink of one Spirit” (1 Cor. 12:13, NASB).

The early church believed the Spirit was much more than some intangible, impersonal force or attitude. They welcomed the Spirit as the indwelling presence of God himself, a presence that had been promised long before. They thankfully recognized that God had delivered them “through the washing of rebirth and renewal by the Holy Spirit” (Titus 3:5).

But they also believed that the Spirit had done more than take up residence in them. They knew that God was doing something powerful among them (just as he continues to do something powerful among his people today) through his Spirit.

From Theology Matters: Answers for the Church Today; in Honor of Harold Hazelip. Chapter 3 “How does the Spirit Work in the Christian?” pp. 34-36