I believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.
And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds; God of God, Light of Light, very God of very God; begotten, not made, being of one substance with the Father, by whom all things were made.
Who, for us men and for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the virgin Mary, and was made man; and was crucified also for us under Pontius Pilate; He suffered and was buried; and the third day He rose again, according to the Scriptures; and ascended into heaven, and sits on the right hand of the Father; and He shall come again, with glory, to judge the quick and the dead; whose kingdom shall have no end.
And I believe in the Holy Ghost, the Lord and Giver of Life; who proceeds from the Father and the Son; who with the Father and the Son together is worshipped and glorified; who spoke by the prophets.
-Nicene Creed (last paragraph omitted)
The Doctrine of the Trinity as Soteriological & Structural Necessity
Another major emphasis in the Gospel of John is the doctrine of the Trinity. This becomes clearer as we examine the book a little more carefully. As I’ve noted elsewhere, the attempt to deny the doctrine of the Deity of Christ, and the doctrine of the Trinity, is impossible, for it is a Scriptural teaching imprinted on practically every page of God’s Word. John’s Gospel shows us the intimacy of the Father and the Son and the Holy Spirit as they work in complete harmony and unison; and the book would be disfigured if one were to try to disrupt this doctrine, for the actions of the Father and of the Son and of the Holy Spirit structure the book’s teaching as a whole. Salvation, moreover, would be negatively affected, for the Three Persons work together in redemption. The Father sent the Son. The Son lived and died for the elect (whom the Father has chosen). And the Holy Spirit regenerates whom He wills (cf. “The” Teacher of Israel Vs. “A” Teacher Come from God).
The following passages have been divided up to (i.) clearly identify each Person of the Godhead and (ii.) their corresponding work. This isn’t by any means an exhaustive list, but is just intended to show how the Trinity saturates John’s Gospel. We see in it a consistent Trinitarian theology that shows the Father sending the Son and the Spirit, the Son dying and raising to life for those the Father has given to Him, and the Spirit raising to life those for whom Christ died (revealing the kingdom of God and Christ to them, guiding them into truth about Christ, and keeping them).
|1:33||“He who sent me”-
The Father sends
(both John the Baptist and the Lord Jesus)
|“this is He who baptizes with the Holy Spirit”-||“the Spirit descends”-
The Holy Spirit reveals Christ (here to John the Baptist)
|3:5-18||[vv.16-18]The Father sends
Christ to die for the sinners
|[vv.10-15]The Son is the promised Deliverer sent to die for sinners||[vv.5-8]The Holy Spirit regenerates men so that they can see the kingdom|
|3:34||“God has sent…He gives the Spirit…”
The Father has sent Christ, to whom He has given the Spirit without measure
|“He whom God has sent…”-
Jesus speaks the Words that the Father has given Him, He, as the only begotten Son of God, uniquely testifies of heavenly things
The ministry of the Lord Jesus is marked by the power of the Holy Spirit
|4:10-26||[vv.21-24]The Father is to be worshipped in spirit and in truth||[vv. 10; 25-26]The Son grants the gift of salvation; He is the promised Messiah||[vv.13-14]The Holy Spirit regenerates us that we might worship the Father in spirit and in truth|
|6:27-63||[vv.27, 29b & 32-33]The Father sent the Son||[vv. 29; 32-33; 38-40]The Son has been sealed and sent by the Father into the world, gives eternal life, preserves those to whom He has given eternal life, and raises them||[v.63]The Holy Spirit regenerates sinners|
|7:16-39||[vv.16-18]The Father has sent the Son into the world||[vv.28-29]The Son has been sent from the Father and will return to Him||[vv.37-39]The Holy Spirit will in-dwell those whom He regenerates|
|14:16-17||The Father will give them the Holy Spirit||The Son will pray the Father sends the “Spirit of Truth”/”Helper”/”Comforter”||The Holy Spirit will be with the disciples/believers forever|
|14:26||The Father will send the Holy Spirit in the name of Christ||The Son is going back to the Father||The Holy Spirit will bring to remembrance all that the Son has said, etc|
|15:26||The Father is who the Spirit proceeds from||The Son sends the Spirit from the Father||The Spirit proceeds from the Father|
|16:5-33||[v.23]The Father will give whatever is asked in Christ’s name
The Father loves the disciples/believers
The Father is with the Son
|[v.5]The Son is going to the Father (i.e. returning to the glory He shared with the Father since before all time)||[vv.7-13]The Holy Spirit will lead them into all truth, convict the world of sin, righteousness and judgment, and glorify the Son by taking what is the Son’s and making it known to them|
|20:21-22||The Father sent the Son||The Son sends the disciples/believers||The Holy Spirit indwells the disciples/believers|
 I haven’t listed all that each Person of the Trinity does (e.g. the Father draws His elect to Christ in John 6:44); and I’m not sure as to whether or not there are more passages in John’s Gospel that show the Trinity working in unison. If you’ve got any suggestions, please let me know!