The prayer you have lifted up from the Apostle’s letter is a prayer for nothing less than the complete renovation of the inner man. To be strengthened with might through His Spirit, so that Christ may dwell in your heart through faith, this is not a small request. It is to ask that the very soil of your soul be made fit for the indwelling of the King. For where the Spirit is, there is Christ. Where one Person of the undivided Trinity is present, the whole Trinity is present. You have, then, asked rightly, for the Spirit does not come to us as an inferior consolation, but as the very power that removes death, enmity against God, and the inability to keep His laws, bringing instead life and righteousness.
You long to know the love of Christ which passes knowledge. But consider this wonder: how can we grasp what is beyond all human knowing? Not by the strength of our own reason, which reels and faints at such a height, but by the very condition you have named: having Christ dwelling within. When the Son and the Spirit take up their abode, they bring their own love with them. The comprehension of that width and length and depth and height is not a prize won by intellectual striving; it is a grace revealed to those who are rooted and grounded in love, whose hearts have become a habitation for God. It is life, not mere learning.
Yet mark what must follow. The Spirit is called the "Spirit of Truth," and His life in us makes the body dead to the working of sin. This is not a figure of speech. To be filled with the Spirit is to have your members become like those of one laid out for burial, insensible to the old, corrupting desires. If you would run the race without being weighed down, this is the path. The body is not abolished, but its vicious tyranny is overthrown. Living by the Spirit is life indeed, an immortal life that wears out death itself. This is the righteousness that proves the Spirit's indwelling.
You desire to be filled to all the fullness of God. This fullness is the life of all virtue, for God is full of every good. But it is also a life of thanksgiving and holy song. The Apostle commands that we be filled with the Spirit, speaking to one another in psalms and hymns, singing and making melody in the heart to the Lord. This is the music that accompanies the indwelling, a constant gratitude that fills not only the tongue but the hidden chambers of the heart, offered in the name of our Lord Jesus Christ to God the Father.
Do not be confounded if you find yourself waiting and longing. For consider the pattern of the Apostles themselves. The Lord promised them the Spirit, yet the Spirit did not come while Christ was present, nor even immediately after His departure. There was a season of longing, a space of some days when their desire was intensified. It was fitting that they should first feel their need keenly, so that when the grace did descend, the joy would be unalloyed and the consolation complete. Our nature had to be seen enthroned in heaven and the reconciliation perfected before the Spirit came to bring that full and certain joy. Your present yearning, then, is not a denial of the promise but a preparation for it. Do not let sorrow fill your heart, but let this longing fix your eyes more firmly on the One who knows your despondency and answers it.
The Spirit is sent by the Son from the Father, a witness to the truth and the One who baptizes with holy fire. If you have taken a tender shoot of faith, do not imagine that you must be watered with such power because the Spirit is weak. Far from it. The greater matters of teaching and consolation were reserved for the Spirit’s coming, that we might know He is in no way inferior but is Himself God, bringing the whole Trinity to dwell in the soul. Therefore, give place to God’s providence. Flee vice, and cling to virtue. The One who began this good work in you is able to do exceedingly abundantly above all that we ask or even think, according to the power that works in us. To that God, Father, Son, and Holy Spirit, be glory forever. Amen.