The unity under and in Christ of the Faithful on earth (the Church Militant), the souls in purgatory (the Church suffering) and the blessed in heaven (the Church Triumphant); it is shared in by the angels and by those non-Catholics in good faith who belong to the soul of the Church.
1 Cor. 12:26-27: – If one member suffers, all suffer together; if one member is honored, all rejoice together. 27 Now you are the body of Christ and individually members of it.
Eph. 1:22-23 – he has put all things under his feet and has made him the head over all things for the church, 23 which is his body, the fullness of him who fills all in all.
Eph. 5:21-32 – Christ is head of church, savior of the body.
Col. 1:18, 24 – he is the head of the body the church.
Rom. 12:5 – so we, though many, are one body in Christ, and individually members one of another.
Rom. 12:10 – love one another with brotherly affection; outdo one another in showing honor.
1 Thess. 5:11 – Therefore encourage one another and build one another up, just as you are doing.
Gal. 6:2 – Bear one another’s burdens, and so fulfil the law of Christ.
Gal. 6:10 – So then, as we have opportunity, let us do good to all men, and especially to those who are of the household of faith.
St. Cyprian of Carthage [AD 252] “Let us remember one another in concern and unanimity. Let us on both sides pray for one another. Let us relieve burdens and afflictions by mutual love, that if one of us, by the swiftness of divine condescension, shall go hence the first, our love may continue in the presence of the Father’s mercy” (Letters 56[60]:5).
Origen [AD 233] “But not the high priest [Christ] alone prays for those who pray sincerely. But also the angels…as also the souls of the saints who have already fallen asleep” (On prayer 11).