The Church as the necessary means of salvation for humankind. All who are saved, therefore, receive the necessary grace somehow through the visible Church founded by Christ.
I once heard a priest say that we can (in a manner of speaking) say that Jesus Christ is the “sacrament” of God, in the sense that Jesus makes the invisible God visible among men. The Church can be thought of as a “sacrament” of Jesus, in that sense ... He is visible on earth in the Church’s members, collectively.
It’s not a perfect formulation of course, but I’ve found it gives me some food for thought.