That Christ may dwell in your hearts by faith. — What that indwelling power is he now indicates, so passing to another Person of the Holy Trinity. It is (see Colossians 1:27) “Christ in you, the hope of glory.” The indwelling of Christ (as here the construction of the original plainly shows) is not a consequence of the gift of the Spirit; it is identical with it, for the office of the Holy Spirit is to implant and work out in us the likeness of Christ. So in John 14:16-20, in immediate connection with the promise of the Comforter, we read: “I will not leave you orphaned; I will come to you.” “Ye shall know that... ye are in me and I in you.” Hence the life in the Spirit is described as “To me to live is Christ” (Philippians 1:21); “I live, yet not I, but Christ liveth in me” (Galatians 2:20). Faith is simply the condition of that indwelling of Christ (comp. Ephesians 2:8), the opening of the door to Him that He may enter in.
The prayer is here complete, all that follows being but consequent from it. In accordance with the universal law of revelation, all is from the Father, all is through the Son vouchsafing to tabernacle in our humanity, all is by the Spirit effecting that indwelling of Christ in each individual soul.
That ye, being rooted and grounded in love. — The phrase “ye, being,” &c., stands in the original before the word “that,” as a kind of link between the previous clause and this, which seems to describe the consequence of the indwelling of Christ — viz., first love, next comprehension, and finally growth into the fulness of God.
The expression “rooted and grounded” (i.e., founded) contains the same mixture of metaphor as in 1 Corinthians 3:9, of the tree and the building — a mixture so natural as to pass into common usage. (Comp. Colossians 2:7, “rooted and being built up in Him.”) The idea implied in “rooted” is of the striking down deeper and spreading wider into the soil; in “founded” of the firm basis on which ultimately we rest. “In love:” Love is not itself the root or foundation (for this is Jesus Christ Himself), but the condition under which growth takes place. Generally that growth is upward, as in 1 Corinthians 8:1 : “Knowledge puffeth up, but love buildeth up;” or, as in Ephesians 4:16, where the body is said “to build itself up in love.” Here that growth is downward, deeper and deeper into the communion with God in Christ, as “faith is made perfect (or, efficient) by love.” As in relation to man, so also to God, love is at once the recognition of an existing unity between spirit and spirit, and a means — probably the only means — of making that unity energetic and deepening it continually. Hence love is the first consequence of the indwelling of Christ in the soul; and by it the soul becomes rooted and grounded in the unity, given by that indwelling, with man and God.