The premise he's getting to here was true even before the New Covenant, wasn't it? The injunction to love one's neighbor as oneself predates Christ. Or is that not relevant?
I think he's saying that one can do that supremely through the Eucharist and it's binding power, but he uses the word authenticity here, which makes me nervous. The Holy Father used it too, made me nervous then too, because the Eucharist assists the person in his striving for Theosis, and It does so on a very individual, "I knew you when you were in the womb", "every one of the hairs on your head is numbered" basis.
When one uses the word authenticity in relation to proper disposition of reception of the Eucharist, it seems an extreme presumption to me, that differs immeasureably from the Spriritual advising of a Child of God to refrain from reception of the Holy Eucharist while in a state of grave sin.
My ultimate journey to Our Lord will provide the Communion he speaks of, but we are all in need of individual sculpting based on our weaknesses and strengths.
Maybe I just don't fully understand what he's getting at, but if I do, I don't think I see things as he does.
He may make a good Pope, I don't know that much about him, so I can't say for sure.
* I think Card. Ratzinger is speaking about what must follow Eucharist. Try re-reading what you highlighted.
"The premise he's getting to here was true even before the New Covenant, wasn't it? The injunction to love one's neighbor as oneself predates Christ. Or is that not relevant?"
Relevant to me in this sense, this comment as well as more in the linked piece again seems to me to evince a sort of worldliness, or perhaps better said, a focus on the cares and tribulations of the world in a universal sense. I am not saying that we shouldn't be concerned for our brother's welfare, but I get the feeling what the Cardinal is talking about is a material sort of welfare, that that is the paramount concern rather than his spiritual welfare and in strengthening each other to keep our eyes focused on the mark, which is God. Of course, we all fail at that everyday, but keeping our eye on the mark has to be our primary goal.