Well, now that may be a problem. I understand that the Church interprets the Apostles. But who interprets the individual interpreters, especially on stuff that is not in consensus with the Church?
The Eucharist is not a human ritual. Humans cannot turn wine into blood, and rituals cannot save. It is a sacrament ordinarily necessary for salvation, yes, ...
Sure it's a human ritual:
Ritual:
1. a. The prescribed order of a religious ceremony. b. The body of ceremonies or rites used in a place of worship. (FOD)
Besides, you do say that humans can forgive sins, so that would make confession a ritual AND salvific.
So, you disagree with the early Church, period. You find something in Augustine that you use as a jumping off point.
While I think that Augustine was closer to scripture on many points than most (maybe all) of the others, I don't think the early Church was wrong about everything. We couldn't consider each other Christians otherwise. :)
If such individual is not in consensus with the Church, then that is the final judgement on him.
it's a human ritual
Ye,s there is a rutualistic element to all sacraments, but it is not their essence. It is incorrect to describe sacraments, that involve the Divine grace, as a ritual.