I think that this disagreement of the Church being an institution is amissunderstanding of context. When Paul spoke of THE CHURCH, he was speaking of all those who inherited the gift of being sons of God. This is why I do not think that the church is an institution, but rather a nation. The Church is the promised seed of Abraham(Galations 3:26 - 4:7). I think this is were confussion enters in. I think what we call THE CHURCH, you call THE BODY of CHRIST. What you call THE CHURCH, I call the assembly of the church. Does this make sense? I dont think of the Catholic Church as a church, but rather a collection of members of the body of Christ, under the authority of the Apostolic succession.
You are correct that The Church is a nation. More particularly:
St. Peter told the first Christians: You are a chosen race, a royal priesthood, a holy nation, a people set apart by God to proclaim his saving deeds, who called you out of darkness into his marvelous light (1 Pt 2:9).
Catholic are baptised Priest, Prophet and King since we share in those same attributes as our heavenly leader - Jesus.
The Catholic Church is the true Church founded by Jesus Christ, whose members are joined by bonds of spiritual communion: loyalty to the Pope and bishops joined with him, oneness in the truths to be believed and the moral code to be followed, oneness in worship. The Church is a mystery, the sacrament of salvation and the People of God journeying together toward eternal life. (771-776)
While all faiths reflect the truth and goodness of God, only one can be the true faith. The fullness of Jesus’ revelation-the truths to be believed, the way of life, the gifts of grace-subsists (is totally present) in the Catholic Church. (816, 830)
He has put all things under his feet and has given him as head over all things to the Church, which is his body, the fullness of the One who fills all things in their totality (Eph 1:22-23).
The term “Mystical Body” refers to the real union of the Church’s members (living and deceased) with Jesus, who is the Head, and with one another through the grace-giving activity of the Holy Spirit. (787-795)
For just as we have many members in one body…in the same way we, many as we are, are one body in Christ, and each one of us is a part of the other (Rom 12:4-5). (See also 1 Cor 12:27; Jn 15:4-5)
The true Church founded by Christ is one, holy, catholic (or universal) and apostolic. Only the Roman Catholic Church has these four characteristics or marks. (811-812)
Rooted in the mystery of the Trinity, the Church’s unity consists especially in the bond of charity. It becomes visible in profession of the same faith, common worship, and union with the Church’s pastors. (813-822)
There is one Body and one Spirit, just as you were called to the one hope of your calling. One Lord, one faith, one baptism, one God and Father of us all, who is above all, through all, and in all (Eph 4:4-5).
Christ gave his life to make the Church holy and sent the Spirit to breathe holiness into it. Since all the Church’s members are called to holiness, Christ gave the Church the means to help them toward this goal, especially the sacraments. (823-829)
In him the whole building is joined together and grows into a holy Temple in the Lord, and in him you are being built together into God’s dwelling place in the Spirit (Eph 2:21-22).
The Catholic Church is necessary for salvation because Christ wills to give us the grace of salvation through his Church. In some way this grace reaches even those who are not members of the Church. If through no fault of their own they do not know our Savior Jesus Christ and his Church, they can be saved if they seek God sincerely and try to live good lives. (846-848)
In Christ we have free and confident access to God through our faith in him (Eph 3:6).
James