Most assuredly, I say to you, the Son can do nothing of Himself, but what He sees the Father do; for whatever He does, the Son also does in like manner. (John 5:19)
He who has seen Me has seen the Father; so how can you say, ‘Show us the Father’? “Do you not believe that I am in the Father, and the Father in Me? The words that I speak to you I do not speak on My own authority; but the Father who dwells in Me does the works. “Believe Me that I am in the Father and the Father in Me, or else believe Me for the sake of the works themselves. (John 14:9-11)
the Father is in Me, and I in Him. (John 10:38)
dwell and are established firmly in one another. For they are inseparable and cannot part from one another, but keep to their separate courses within one another, without coalescing or mingling, but cleaving to each other. For the Son is in the Father and the Spirit: and the Spirit in the Father and the Son: and the Father in the Son and the Spirit, but there is no coalescence or commingling or confusion. (De Fide Orthodoxa, I.14).
Because of this mutual indwelling, what one Person of the Godhead is involved in doing, the others are involved in doing too. So, the baptism in the Holy Spirit isn't just something to do with the Holy Spirit, but involves the whole Trinity.
And I think that keeping sight of the fact that Spirit Baptism is a Trinitarian work helps guard us from losing sight of the great reality of what it really is. You see, by looking at it as only the work of the Spirit, it suddenly becomes easy to lose sight of the personality of God the Holy Spirit. Rather than realising the wonder of such an encounter with God the Spirit, people often simply seem to turn the Spirit in their thinking into simply the power of God. But the Holy Spirit is not power from God — He is God Himself!
But not only does perichoresis remind us that Spirit baptism is an encounter with a personal God (as opposed to merely a divine power), but it also helps us understand something about the fullness that comes from Spirit baptism.
In the book of Acts, baptism in the Holy Spirit is also referred to as being filled with the Holy Spirit, and various believers are noted as being full of the Holy Spirit. Already, we see that that is full of God the Holy Spirit, not simply full of divine power. But the Trinitarian doctrine of perichoresis helps us to see something else too; for, if there is a mutual indwelling of the Persons of the Godhead, and Christians are filled with the Holy Spirit, then Christians are also filled with the Father and the Son who indwell the Spirit!
In John 14, as Jesus concludes some teaching on the coming of the Holy Spirit, He suddenly declares, "I will not leave you orphans; I will come to you." (John 14:18). Due to His mutual indwelling with the Spirit, that makes perfect sense; Christ comes to us by the Spirit. When we are filled with the Spirit we are filled with Christ. A few verses later Jesus tells us that, to only will He come to us, but the Father will as well:
Jesus answered and said to him, “If anyone loves Me, he will keep My word; and My Father will love him, and We will come to him and make Our home with him. (John 14:23)
The Father is seated on the Throne and Jesus at His right hand, so how can this be? Through the Spirit! When the Holy Spirit comes, He brings the Father and Son who indwell Him with Him.
And seeing that points us to both the wonder and importance of baptism in the Holy Spirit. It is wondrous for the God of all creation, theGod of our salvation, stoops down to dwell in mere human beings. And it's importance, because of the stated purpose of the Triune God.
You see, in Ephesians, where we read of God's Eternal Purpose, we read that Christ died, rose and "ascended far above all the heavens that He might fill all things" (Eph. 4:10). And that fullness of Christ is the goal of the growth of the Church (Eph. 4:13). Paul's prayer for the Church is that it be "filled with all the fullness of God" (Eph. 3:19). But now, the truth of perichoresis helps us to see the role of the baptism and fullness of the Holy Spirit in this eternal purpose of God in Christ for the Church. For as we are filled with the Spirit, we are filled with Christ and filled with God the Father!
Now, don't get me wrong. I'm not saying that the baptism in the Holy Spirit is God's eternal purpose for the Church. The Eternal Purpose is clearly much more than that. But what we can see is that the baptism in the Holy Spirit has an important role to play.
So, the baptism in the Holy Spirit is a Trinitarian encounter in which Jesus fills us with Himself and with the Father through filling us with the Spirit. What wondrous grace!