“and to know the love of Christ which surpasses knowledge, that you may be filled up to all the fullness of God.” (vs. 19)
The Greek understanding of this verse is:
And to understand with extraordinary knowledge the supernatural love of Christ, which goes way beyond head knowledge, that you might be filled unto all the fullness of God.
γνῶναί – speaks of knowledge that goes beyond the merely factual and into the realm of the experiential.
ὑπερβάλλουσαν – literally means throwing beyond the usual mark and figuratively referring to a degree which exceeds extraordinary, a point on an implied or overt scale of extent. Expressing a degree beyond comparison.
“Paul wants the readers to be empowered so as to know the love of Christ which surpasses knowledge. Note that this is not a petition that the believers might love Christ more, as important as that is, but rather that they might understand in the experiential dimension Christ’s love for them.” (http://www.preceptaustin.org/ephesians_318-19.htm) Put simply, this word describes the intimacy between a husband and his wife or God and his people.
The “love of God” here cannot be put into words, but is the unconditional, sacrificial love which God is. It is the 1 Cor 13 type of love.
Kenneth Wuest translates the last part of this verse beautifully by saying, “that you may be filled up to the measure of all the fullness of God.” “Paul’s prayer to the Father reaches its climax in this final, summarizing request. Thus we note that as believers are strengthened in the inner man through the Spirit and Christ dwells comfortably at home in their hearts through faith and they know in a personal, experiential way more of the immeasurable love of Christ, based on these spiritual dynamics, believers will be filled to the measure of all the fulness of God.” (http://www.preceptaustin.org/ephesians_318-19.htm)
So the filling talked about here at the end of verse 19 is the result of verse 17-19a becoming a reality in our innermost being. The fullness of God is power, and we are empowered, literally made powerful (in a good way) through experientially knowing that we are love by God! There is nothing conceivable beyond the fullness of God. It is all the divine perfections of the Godhead as expressed in Jesus. THIS IS THE GOAL, TO KNOW THAT WE ARE LOVED!!!