The apostle prays that his readers may know the love of Christ. This is a part of the Divine plenitude; nor is there anything in it deeper. But there is more to know. When he asks for "_all_ the fulness," he thinks of other elements of revelation in which we are to participate. God's _wisdom_, His _truth_, His _righteousness_, along with His _love_ in its manifold forms,--all the qualities that, in one word, go to make up His _holiness_, are communicable and belong to the image stamped by the Holy Spirit on the nature of God's children. "Ye shall be holy, for I am holy" is God's standing command to His sons. So Jesus bids His disciples, "Be perfect, as your Father in heaven is perfect." St Paul's prayer "is but another way of expressing the continuous aspiration and effort after holiness which is enjoined in our Lord's precept" (Lightfoot).
While the holiness of God gathers up into one stream of white radiance the revelation of His character, "the fulness of God" spreads it abroad in its many-coloured richness and variety. The term accords with the affluence of thought that marks this supplication. The might of the Spirit that strengthens weak human hearts, the greatness of the Christ who is the guest of our faith, His wide-spreading kingdom and the vast interests it embraces and His own love surpassing all,--these objects of the soul's desire issue from the fulness of God; and they lead us in pursuing them, like streams pouring into the ocean, back to the eternal Godhead. The mediatorial kingdom has its end; Christ, when He has "put down all rule and authority," will at last "yield it up to His God and Father"; and "the Son Himself will be subjected to Him that put all things under Him, that God may be all in all" (1 Cor. xv. 24-28). This is the crown of the Redeemer's mission, the end which His love to the Father seeks. But when that end is reached, and the soul with immediate vision beholds the Father's glory, the Plenitude will be still new and unexhausted; the soul will then begin its deepest lessons in the knowledge of God which is life eternal.
St Paul is conscious of the extreme boldness of the prayer he has just uttered. But he protests that, instead of going beyond God's purposes, it falls short of them. This assurance rises, in verses 20 and 21, into a rapture of praise. It is a cry of exultation, a true song of triumph, that breaks from the apostle's lips:--