ἐξισχύω

ἐξισχύω means to have strength enough, to be fully able, to be empowered to the point of capability. It is a compound of ἐκ (out of, fully, intensively) and ἰσχύω (to be strong, to have strength). The prefix ἐκ carries an intensive force here: not merely to be somewhat able, but to be thoroughly empowered; to have the strength brought all the way out, all the way through, to completion. The local Greek index currently represents this as a single-occurrence NT word, and that occurrence falls at one of the most concentrated theological moments in Paul's writing.

Ephesians 3:18 reads: 'that you may have strength to comprehend (ἐξισχύσητε καταλαβέσθαι) with all the saints what is the breadth and length and height and depth.' This is the object of Paul's second major prayer in Ephesians (3:14-21). He is praying that his readers, already rooted and grounded in love (v. 17), would be fully empowered to comprehend a dimension of love that exceeds all human capacity to comprehend: the four-dimensional immensity of Christ's love (v. 19, 'which surpasses knowledge').

The verb is not asking for mere intellectual understanding of a concept. Paul is asking that God strengthen his readers in their inner being (v. 16), that Christ dwell in their hearts through faith (v. 17), so that they would have the capacity, the full spiritual strength; to take hold of something that the unstrengthened mind cannot reach. The love of Christ surpasses knowledge, yet Paul prays they would know it. The resolution is not contradiction but the distinction between comprehending with the strengthened inner self versus grasping with unaided cognition. ἐξισχύω is the word for the capacity that only the Spirit's empowerment can produce.

Ephesians 3:14-21 is one of Paul's two great prayers in this letter (cf. 1:15-23), and it is addressed to a church that has just been told in chapters 1-3 the most astonishing things about who they are in Christ: chosen before the foundation of the world, predestined for adoption, sealed with the Holy Spirit, made alive together with Christ, raised and seated in the heavenly places, created for good works, brought near by the blood of Christ, made members of one household with Israel's saints, and made the dwelling place of God in the Spirit. Having said all that, Paul falls on his knees (v. 14, the only place in the NT where Paul explicitly takes this posture for prayer) and asks for more. The 'more' is not more information but more capacity to hold what has already been said.

The prayer structure is: be strengthened in the inner person by the Spirit (v. 16) so that Christ may dwell in your hearts (v. 17), so that, being rooted and grounded in love, you may have the strength (ἐξισχύσητε) to comprehend (v. 18) the four dimensions of Christ's love, and come to know it (v. 19a), which is a love that surpasses knowledge (v. 19b), so that you may be filled with all the fullness of God (v. 19c). The sequence matters. ἐξισχύω is not the beginning of this prayer but the third step, the capacity-step. It comes after inner strengthening and Christ's indwelling. You cannot ἐξισχύω your way to comprehending the love of Christ from outside, the interior work of the Spirit is what produces the capacity.

The four-dimensional language; breadth, length, height, depth; is deliberately unmeasurable. Paul is not giving geometric coordinates of Christ's love. He is using the language of spatial totality to say: in every direction you could extend a measurement, Christ's love exceeds it. The prayer is that the saints would have the strength to take hold of this immensity, not merely to nod at it. ἐξισχύω is the right word because this is not comprehension as passive reception of information but active spiritual apprehension, the soul being stretched toward something it cannot reach without being strengthened from outside itself.

The doxology that closes the prayer (3:20-21) confirms the direction: 'to him who is able (δυναμένῳ) to do far more abundantly than all we ask or think, according to the power at work within us.' The prayer that invokes ἐξισχύω for the saints closes by crediting God's own δύναμις as the ground. The fully-able God is the source of the saint's being-fully-able. ἐξισχύω in the believer is the derivative expression of δύναμις in God.