Glory be to the Father,” sings the church, “and to the Son, and to the Holy Ghost.” What is this? we ask—praise to three gods? No; praise to one God in three persons. As the hymn puts it,

Jehovah! Father, Spirit, Son!

Mysterious Godhead! Three in One!

This is the God whom Christians worship—the triune Jehovah. The heart of Christian faith in God is the revealed mystery of the Trinity. Trinitas is a Latin word meaning threeness. Christianity rests on the doctrine of the trinitas, the threeness, the tripersonality, of God.

It is often assumed that the doctrine of the Trinity, just because it is mysterious, is a piece of theological lumber that we can get on very happily without. Our practice certainly seems to reflect this assumption. The prayer book of the Church of England prescribes thirteen occasions each year when the Athanasian Creed, the classic statement of this doctrine, should be recited in public worship, but it is rare today to find it used on even one of these. The average Anglican clergyman never preaches on the Trinity except perhaps on Trinity Sunday; the average nonliturgical minister, who does not observe Trinity Sunday, never preaches on it at all. One wonders what the apostle John would say, were he here to comment on our practice. For according to him the doctrine of the Trinity is an essential part of the Christian gospel.

In the opening sentences of his Gospel, as we saw in our last chapter, John introduces us to the mystery of two distinct persons within the unity of the Godhead. This is the deep end of theology, no doubt, but John throws us straight into it. “In the beginning was the Word, and the Word was with God, and the Word was God” (Jn 1:1). The Word was a person in fellowship with God, and the Word was himself personally and eternally divine. He was, as John proceeds to tell us, the only Son of the Father. John sets this mystery of one God in two persons at the head of his Gospel because he knows that nobody can make head or tail of the words and works of Jesus of Nazareth till he has grasped the fact that this Jesus is in truth God the Son.


But this is not all that John means us to learn about the plurality of persons in the Godhead. For, in his account of our Lord’s last talk to his disciples, he reports how the Savior, having explained that he was going to prepare a place for them in his Father’s house, went on to promise them the gift of “another Comforter” (Jn 14:16 KJV).

Note this phrase; it is full of meaning. It denotes a person, and a remarkable person too. A Comforter—the richness of the idea is seen from the variety of renderings in different translations: “counselor” (RSV), “helper” (Moffatt), “advocate” (Weymouth), one “to befriend you” (Knox). The thoughts of encouragement, support, assistance, care, the shouldering of responsibility for another’s welfare, are all conveyed by this word. Another Comforter—yes, because Jesus was their original Comforter, and the newcomer’s task was to continue this side of his ministry. It follows, therefore, that we can only appreciate all that our Lord meant when he spoke of “another Comforter” as we look back over all that he himself had done in the way of love, and care, and patient instruction, and provision for the disciples’ well-being, during his own three years of personal ministry to them. “He will care for you,” Christ was saying in effect, “in the way that I have cared for you.” Truly a remarkable person!

Our Lord went on to name the new Comforter. He is “the Spirit of truth,” “the Holy Spirit” (Jn 14:17, 26). This name denoted deity. In the Old Testament, God’s word and God’s Spirit are parallel figures. God’s word is his almighty speech; God’s Spirit is his almighty breath. Both phrases convey the thought of his power in action. The speech and the breath of God appear together in the record of creation. “The Spirit [breath] of God was hovering over the waters. And God said . . . and there was . . .” (Gen 1:2-3). “By the word of the LORD were the heavens made, their starry host by the breath [Spirit] of his mouth” (Ps 33:6). John told us in the prologue that the divine Word spoken of here is a person. Our Lord now gives parallel teaching, to the effect that the divine Spirit is also a person. And he confirms his witness to the deity of this personal Spirit by calling him the holy Spirit, as later he was to speak of the holy Father (Jn 17:11).

John’s Gospel shows how Christ related the Spirit’s mission to the will and purpose of the Father and the Son. In one place, it is the Father who will send the Spirit, as it was the Father who had sent the Son (see 5:23, 26-27). The Father will send the Spirit, says our Lord, “in my name”—that is, as Christ’s deputy, doing Christ’s will and acting as his representative and with his authority (Jn 14:26). Just as Jesus had come in his Father’s name (5:43), acting as the Father’s agent, speaking the Father’s words (12:49-50), doing the Father’s works (10:25; 17:4, 12) and bearing witness throughout to the One whose emissary he was, so the Spirit would come in Jesus’ name, to act in the world as the agent and witness of Jesus. The Spirit “proceedeth from [para: ‘from the side of’] the Father” (15:26 KJV), just as previously the Son “came forth from [para] the Father” (16:28 KJV). Having sent the eternal Son into the world, the Father now recalls him to glory and sends the Spirit to take his place.

But this is only one way of looking at the matter. In another place, it is the Son who will send the Spirit “from the Father” (15:26). As the Father sent the Son into the world, so the Son will send the Spirit into the world (16:7). The Spirit is sent by the Son as well as by the Father. Thus we have the following set of relationships:

1. The Son is subject to the Father, for the Son is sent by the Father in his (the Father’s) name.

2. The Spirit is subject to the Father, for the Spirit is sent by the Father in the Son’s name.

3. The Spirit is subject to the Son as well as to the Father, for the Spirit is sent by the Son as well as by the Father. (Compare 20:22: “He breathed on them and said, ‘Receive the Holy Spirit.’”)

Thus John records our Lord’s disclosure of the mystery of the Trinity: three persons, and one God, the Son doing the will of the Father and the Spirit doing the will of the Father and the Son. And the point stressed is that the Spirit, who comes to Christ’s disciples “to be with you forever” (14:16), is coming to exercise the ministry of a comforter in Christ’s stead. If, therefore, the ministry of Christ the Comforter was important, the ministry of the Holy Spirit the Comforter can scarcely be less important. If the work that Christ did matters to the church, the work that the Spirit does must matter also.


But you would not get that impression from reading church history, nor from looking at the church today.

It is startling to see how differently the biblical teaching about the second and third persons of the Trinity respectively is treated. The person and work of Christ have been, and remain, subjects of constant debate within the church; yet the person and work of the Holy Spirit are largely ignored. The doctrine of the Holy Spirit is the Cinderella of Christian doctrines. Comparatively few seem to be interested in it.

Many excellent books have been written on the person and work of Christ, but the number of books worth reading on the person and work of the Holy Spirit, even in this charismatic era, is small. Christian people are not in doubt as to the work that Christ did; they know that he redeemed us by his atoning death, even if they differ among themselves as to what exactly this involved. But the average Christian, deep down, is in a complete fog as to what work the Holy Spirit does.

Some talk of the Spirit of Christ in the way that one would talk of the spirit of Christmas—as a vague cultural pressure making for bonhomie and religiosity. Some think of the Spirit as inspiring the moral convictions of unbelievers like Gandhi or the theosophical mysticism of a Rudolf Steiner. But most, perhaps, do not think of the Holy Spirit at all, and have no positive ideas of any sort about what he does. They are for practical purposes in the same position as the disciples whom Paul met at Ephesus—“We have not even heard that there is a Holy Spirit” (Acts 19:2).

It is an extraordinary thing that those who profess to care so much about Christ should know and care so little about the Holy Spirit. Christians are aware of the difference it would make if, after all, it transpired that there had never been an Incarnation or an atonement. They know that then they would be lost, for they would have no Savior. But many Christians have really no idea what difference it would make if there were no Holy Spirit in the world. Whether in that case they, or the church, would suffer in any way they just do not know.

Surely something is amiss here. How can we justify neglecting the ministry of Christ’s appointed agent in this way? Is it not a hollow fraud to say that we honor Christ when we ignore, and by ignoring dishonor, the One whom Christ has sent to us as his deputy, to take his place and care for us on his behalf? Ought we not to concern ourselves more about the Holy Spirit than we do?


But is the work of the Holy Spirit really important?

Important! Why, were it not for the work of the Holy Spirit there would be no gospel, no faith, no church, no Christianity in the world at all.

In the first place, without the Holy Spirit there would be no gospel and no New Testament…

J. I. Packer, Knowing God (Westmont, IL: IVP Books, 2011).

We have just completed a Study of J.I. Packer’s classic book, Knowing God. It is available as part of Good Questions Have Groups Talking Lesson Subscription Service. It is also available on Amazon