Ephesians 3:18-9, [That you] 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.
Paul does not explain the dimensions that he mentions in this prayer. Later writers would apply these dimensions to the whole of the cosmos and speak of how the form of the cross encompasses and sustains all of creation. Paul does not say that here, though. If anything, the dimensions seem to be explained by what comes next, namely, the love of Christ.
It seems to me that these dimensions most immediately point to the actual, physical dimensions of the cross. Here the physical form of the cross serves as a symbol for the love of Christ since, upon it the definitive work of love was achieved. So, Paul prays that the Ephesians would know the full dimensionality of the CROSS of Christ…which is to say, that they would know the totality of His LOVE. However, the cosmic elements of these dimensions are not at odds with Paul’s thinking. Indeed, Paul would be the first to say that the whole of the cosmos is ordered, reconciled, and harmonized to the Name of God through the work of Christ’s cross (Col.1:15-20).
This, then leads to the purpose of knowing this love: that we might be filled with all the fullness of God Himself. Knowing the full dimensionality of Christ’s Calvary love leads to being filled with the fullness of God Himself. That’s incredible.
What good, what beauty, what truth is left out of that phrase, ‘all the fullness of God’? Surely, nothing is left out. And if that is the case, and if this fullness of God fills us as we comprehend the paschal mystery of Christ’s love—then ALL good, beauty, and truth is bound up, communicated, and received in the knowledge of that love. For His people, there is nothing other than the love of God in Christ upon the resurrection-illumined cross. This is the beginning and end, the height and the depth, the single truth in which all truth is encompassed and perfected.
May we be strengthened to know the cosmic dimensions of this love, and so be filled with all the fullness of God.
