Brothers and sisters:
Grace was given to each of us
according to the measure of Christ’s gift.
Therefore, it says:
He ascended on high and took prisoners captive;
he gave gifts to men.
What does “he ascended” mean except that he also descended
into the lower regions of the earth?
The one who descended is also the one who ascended
far above all the heavens,
that he might fill all things.
And he gave some as Apostles, others as prophets,
others as evangelists, others as pastors and teachers,
to equip the holy ones for the work of ministry,
for building up the Body of Christ,
until we all attain to the unity of faith
and knowledge of the Son of God, to mature manhood
to the extent of the full stature of Christ,
so that we may no longer be infants,
tossed by waves and swept along by every wind of teaching
arising from human trickery,
from their cunning in the interests of deceitful scheming.
Rather, living the truth in love,
we should grow in every way into him who is the head, Christ,
from whom the whole Body,
joined and held together by every supporting ligament,
with the proper functioning of each part,
brings about the Body’s growth and builds itself up in love.
4:7 given to each: Every baptized believer is given spiritual gifts or charisms to be exercised for the good of the Church (1 Cor 12:4–11; 1 Pet 4:10). In this context, Paul focuses on the varied graces connected with ecclesiastical offices (Eph 4:11) (CCC 913).
4:8 When he ascended: A reference to Ps 68:18. Although the wording of Paul’s citation differs from both the Hebrew and Greek versions of this text known to us, it approximates other renditions of the psalm in Aramaic and Syriac. ● Psalm 68 celebrates the triumphal procession of biblical history, when Israel, filing out of Egypt behind Yahweh, was led on its march to the summit of Mt. Zion in Jerusalem. The victories won by the Lord along the way earned him the right to distribute gifts and spoils of war to the Israelites. For Paul, the psalm points forward to the ascent of Jesus into the heavenly Jerusalem after disarming the forces of evil on the Cross (Col 2:15). The Church began to share in this victory when Christ poured out the gifts of the Spirit on Pentecost (Acts 2:33).
4:9–10 A parenthetical explanation of how Jesus fulfills Ps 68. Interpretations differ over the meaning of lower parts of the earth. (1) Some view this expression as a reference to earth itself, to which Christ descended in his Incarnation (Jn 3:13). (2) Others take it to mean the underworld, to which Jesus descended on Holy Saturday before rising again on Easter Sunday. The second view is more likely correct in light of similar expressions in the Greek versions of Ps 63:9 and 139:14 that clearly refer to the underworld of the dead. In this case, Paul is stressing that Christ has charted the extremities of the cosmos, descending to its deepest depths in his Passion and rising above its highest heights at his Ascension. This is not simply a journey through space; rather, it is an expression of Christ’s supreme humiliation and exaltation. ● Several Church Fathers connected this verse with Christ’s descent to the dead, in which he released the captive souls of the righteous and led them up to heaven (1 Pet 3:18–19; CCC 632–33).
4:11 apostles … teachers: Ecclesial ministries associated with the proclamation of the Word. These positions are established to promote unity in the Church by (1) preserving doctrinal purity, (2) warding off false teaching (4:14), and (3) sanctifying people in truth (Jn 17:17–19). These spokesmen of the gospel build up the Body of Christ when they bring believers from immaturity to spiritual adulthood (Eph 4:15; CCC 1575, 2003–4). Other ministerial graces are listed in Rom 12:6–8 and 1 Cor 12:4–11. See note on 1 Cor 12:28.
4:15 speaking the truth: Or, “doing the truth”. By bracing ourselves with the truth, we can resist the wind and waves of false teaching that unsettle the faith of immature believers. Paul is urging readers to grow in their knowledge of Christ (1:17; 4:23; Rom 12:2); otherwise their minds will remain childish, underdeveloped, and vulnerable to dangerous novelties that are contrary to the gospel (Eph 4:14). Here and elsewhere Paul insists that love is the surest means to build up the Church (4:16; 1 Cor 8:1; 13:1–13).
4:16 joined … growth: The same Greek verbs, which here describe the unity and growth of a body, also appear in 2:21, where they describe the integrated construction of a temple. The double use of this language in Ephesians points to a close connection between “body” and “temple” in Pauline theology (see also 1 Cor 6:19). This connection originates with Jesus, whose human body was the temple of his divinity (Jn 2:19–21). Applied to the living assembly of believers, it implies that the Church is a mystical extension of the Incarnation.
“the unity of faith and knowledge of the Son of God”
The building up of the body of Christ occurs to the extent that its members strive to hold on to the truths of faith and to practice charity in the lives. The “knowledge of the Son of God” refers not only to the object of faith—which is the acceptance of Jesus Christ as true God and true man, but also to a vital, intimate, and loving relationship with him. The recognition of our personal obligation to this on-going growth in our relationship, implies the mark of maturity. It is this maturity in discipleship we should all seek to attain.
May the virtues of faith, hope, and love go with you today – DV.
CCC Catechism of the Catholic Church
 The Ignatius Catholic Study Bible: The New Testament (San Francisco: Ignatius Press, 2010), 349–350.