Re: Can "Reformed" Protestantism's approach to theology lead out of Christianity?
Let me start with the first question.
(1) Does "Reformed" Protestantism (Calvinism, the Methodists, Evangelicals, etc.) have a real basis in early Christian traditions and writings to claim that the Communion meal is "only" a symbol and to reject Jesus' real presence in it?
I was confirmed in the PCUSA and went to an Evangelical Christian school. We were taught that the Communion meal was "only" a symbol of Jesus' body, and did not have Jesus' spiritual presence (like Lutherans and Anglicans claim), and especially was not actually Jesus' physical body as Catholicism teaches.
The only reason I remember that the "Reformed" Protestants gave me was that Jesus said to take the communion meal in "memory" of him. But actually when I think critically about this reason, it looks weak. Just because Jesus says to do something in his memory does not mean that He is not present in it. In other words, it seems perfectly to reasonably that if Jesus were in the Communion meal that you would eat it "in His memory."
Another response the Reformed Protestants give is to debunk Catholicism's reasons. Catholicism says that because Jesus says in John's gospel that you must eat His body, then the communion meal must be his body. The Reformed Protestants argue back that Catholics take this too literally. My reaction is that it's true that Jesus spoke in parables and symbols sometimes, but other times he really did mean things literally and physically like the resurrection of his body. So just because the Reformed Protestants show possible weaknesses in Catholicism does not actually directly show that the "Reformed" version must be right. In other words, just because Catholicism hasn't proved its case doesn't mean that the Reformed side has either.
Typically when we want to find out what some religious community thought, we look at their writings. And the early Christians of the 1st to 2nd centuries AD - the time of the apostles or right after it - did produce writings commenting on religion. Does Reformed Protestantism have any solid, direct basis from these writings to show that they believed the Communion meal was "only" a symbol?
It seems instead that the first clear, recorded interpretation of Communion as "only" a symbol and not physically or even spiritually Jesus' body was made in the era of Reformed Protestantism's beginning - about 1400 years after Jesus' and the apostles' time. It looks rather then that this position is a "modern" or Enlightenment Age re-interpretation of what Jesus said and not actually something that the apostles wrote or passed down.