All well and good, but (as much as I don't like proof-versing) you should consider doing a word study on the Greek κοινωνία (koinonia). Particularly in light of 1 Cor 10:16:
The cup of blessing which we bless, is it not a participation (communion - koinonia) in the blood of Christ? The bread which we break, is it not a participation (communion - koinonia)in the body of Christ?
When you hear the words of the Apostle in 1 Cor 11:24-26, where we are commended to do this as often as we drink together of the cup, I'd say the founders of Christianity did not only know something of this -- I would say they were the prime movers of this.
uh, who do you think made the Eucharistic celebration the centerpiece of early Church services?
The "founders of Christianity" notwithstanding, the Christ of Christianity instituted it.
The founder of Christianity is Christ himeself and the apostles.
Where are you getting your strange ideas?
Were not they there at the Last Supper? (Even though they did not understand it fully at the time.)