I set off the Latin original in parentheses like this, (anima), when I think it may be helpful to highlight the underlying Latin for what is (often) turgid English prose (sorry). I have translated Latin vegetare as "to energize". If that sounds too mechanical, then use "enliven" instead.
Next He says, the words that I have spoken to you are spirit and life (v. 63). For, brethren, I have already said that the Lord had commended, in the eating of His flesh and the drinking of His blood, that we should abide in Him, and He in us. We abide in Him when we are His members, and He abides in us when we are His temple. But for us to be His members, unity links us together (compaginat). What causes unity to link us together but charity? And where does God’s charity derive? Ask the Apostle. He says, because God's love has been poured into our hearts through the Holy Spirit which has been given to us (Rom 5, 5).
That is why it is the Spirit who gives life, for the Spirit makes living members. And even the Spirit does not make living members unless the Spirit Himself shall find them in the body that He energizes (vegetat). For the spirit which is in you, Oh man, by which you exist as a man, does that [natural] spirit give life to any member it finds separated from your flesh? I call your spirit your soul (anima). Your soul does not give life (vivificat) except to the members which are in your flesh: if you remove one, it is no longer given life by your soul, because it is not joined to the unity of your body.
These words, then, are spoken so that we love unity, and fear separation. For the Christian must dread nothing so much as to be separated from the body of Christ. For, if he is separated from the body of Christ, he is not one of His members, and if he is not one of Christ’s members, he is not energized (vegetatur) by the Holy Spirit. The Apostle says, Any one who does not have the Spirit of Christ does not belong to him (Rom 8,9).
It is the spirit that gives life, the flesh is of no avail; the words that I have spoken to you are spirit and life (v. 63). What does “are spirit and life” mean? They ought to be understood spiritually. Do you understand Him spiritually? Then, they are spirit and life. Do you understand Him carnally? Even so, His words are spirit and life, but not for your benefit.
What do I take away from this? a) To be "linked" to Christ is to be Christian; b) To be "linked" to Christ one must be a "member" of His body; c) to be a "member" of His body, one must host Christ by being "connected" by the Holy Spirit; d) to be "connected" by the Holy Spirit, is to be given life as a member of a "structure" of Life which derives from the Blessed Trinity, which is energized in the reception of Christ's body and blood, and which leads now, and hereafter, to Eternal Life; e) that nourishment is provided in the Sacrament of the Eucharist, that is served by the Catholic Church.