". . . that you, being rooted and grounded in love, may have strength to comprehend with all the saints what is the breadth and length and height and depth, and to know the love of Christ that surpasses knowledge, that you may be filled with all the fullness of God."
- Ephesians 3:17b-19
It is the love of Christ - i.e., his love for us, which passes knowledge. It is infinite because of the sufferings to which it led and the blessings which it secures for its objects, which are beyond our comprehension. This love of Christ, though it surpasses the power of our understanding to comprehend, is still a subject of experimental knowledge. We may know how excellent, how wonderful, how free, how disinterested, how long-suffering, how manifold and constant it is, and that it is infinite. And this is the highest and most sanctifying of all knowledge. Those who know the love of Christ for them in this way purify themselves, even as he is pure.- Charles Hodge from his commentary on Ephesians