We believe that God is the ground of all being,
That he entered into his creation through the incarnation
And that he indwells us as a constant reality.
These three facets of God’s interaction with creation remain the consistent ground of Christian faith and understanding of God. They are the reality through which we experience the world that God has created. This reality is not impersonal, but fully personal, so personal in fact that each of these facets should be considered to be personally distinct from one another, so much so that we see these realities interacting one with another in such a way that we must confess that there is personal interaction between these facets. Yet still
שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהוָ֥ה אֱלֹהֵ֖ינוּ יְהוָ֥ה אֶחָֽד
Hear, O Israel, the Lord your God, the Lord is one.
There is something about this ultimate reality that is truly unnerving, this tripersonal God breaks our ability to understand, confronts our preconceptions.
What it means for us as we are indwelt and conformed to the image of the incarnate one is that we participate in this tripersonal life, we do not relate to God merely as one person. But relate to him as three persons, for there are three ways that he intensely relates to us. This intensity is so great that we must relate to him tripersonally or else deny his divinity. We must consider all three persons God because they are the windows through which we perceive the divine, John talks about this in his opening of his Gospel,
Θεὸν οὐδεὶς ἑώρακεν πώποτε· μονογενὴς θεὸς ὁ ὢν εἰς τὸν κόλπον τοῦ πατρὸς ἐκεῖνος ἐξηγήσατο
No one has ever seen God: the unique God who dwells in the bosom of the Father, he has made him known.
Through the person and work of Jesus, John says, we see the true reality of being, and not just a reflection, but the more mighty wonder of the face of God, to know Jesus intimately is to know the Father, not just because they are of the same purpose, but because they are the one and the same being seen from two different vantage points, Moses saw the back of God, but we now with unveiled faces look upon Jesus, the full revelation of God.
and of the indwelling Jesus says,
Οὐκ ἀφήσω ὑμᾶς ὀρφανούς, ἔρχομαι πρὸς ὑμᾶς.
I will not leave you as orphans, I will come to you…
γνώσεσθε ὑμεῖς ὅτι ἐγὼ ἐν τῷ πατρί μου καὶ ὑμεῖς ἐν ἐμοὶ κἀγὼ ἐν ὑμῖν.
You will know that I am in my Father, and you in me and I in you…
καὶ πρὸς αὐτὸν ἐλευσόμεθα καὶ μονὴν παρʼ αὐτῷ ποιησόμεθα.
And we will come to him and make our home with him...
The Spirit by his catching us into the life of Christ weaves us into the triune life of God, not so that we might participate in divinity, but so that we might live our lives conformed to God and pursuant of Him. The reality of living in the midst of God is not such that we might be made much of, but so that God might be glorified in our stepping out, we bear in our bodies the life and death of Christ, this is so that we might bring God’s creative redemption to the world. We are the means by which the Kingdom of God is breaking in and He is making all things new, and this can only take place if God is with us, if God is merely the ground of being then there is no ability for us to be the bearers of His good news. If God were merely the broken man on the Cross then creation would have fallen apart for three days and nights, if God were merely the indwelling presence of the Spirit then there would be no salvation open to us. God must be all three, all three must be personal, or else there is no good news.