Why is Sabellianism a heresy?

[avertist]

Not that I in particular need to be convinced, but I've been having trouble locating information about Eastern responses to Sabellianism (or Modalism, the belief that God is one person with three "parts"). In particular, one explanation of the Trinity that I hear a lot in charismatic "Campus Crusade" type congregations is that the Father, Son, and Holy Spirit are just the Mind, Body, and Soul respectively of God. Though this doesn't seem particularly offensive to reason, it certainly smells like Sabellianism to me.

[moses916]

the trinity consists of 3 persons, 3 parts is blasphemy!

[Matrona]

In short, Sabellianism is heresy because it denies the individual personhood of each member of the Trinity. The truth is that they are co-equal and co-eternal and have the same nature.

If I were you I'd stay away from Campus Crusade, I used to be involved in that and it operates more like a pyramid scheme than a Christian organization interested in saving souls.

[avertist]

Yes, I understand that it *is* a heresy, and I do stay away from Campus Crusade for the most part, but what I'm looking for is arguments against it from whichever Orthodox theologians were around at the time to condemn it (if any).

edit - For instance, Wikipedia says "Sabellianism was also embraced by Christians in Cyrenaica, to whom Demetrius, Patriarch of Alexandria, wrote letters arguing against this belief." Does anyone know where I could find these writings?

[Rilian]

I looked around avertist and I can't find anything, they may be somewhat obscure. Two works that cover related ground are Against Heresies (http://www.ccel.org/fathers2/ANF-01/TOC.htm#TopOfPage) by St. Irenaeus of Lyons (scroll down on the page) and On the Incarnation (http://www.orthodoxonline.com/incarnation.pdf) by St. Athanasius (it's a pdf).

[Marjorie]

Sabellianism is a heresy because it turns God into a monad instead of the dynamic Personal God we see revealed in the doctrine of the Trinity. If you want an explanation of Trinitarian doctrine as revealed in the Fathers like no other, which will indirectly explain why Sabellianism is a problem, look up Being and Communion by Metropolitan John (Zizioulas.) Fr. John Behr's The Way to Nicaea also talks a bit about early Sabellianists and views of the Trinity and so on.

In IC XC,
Marjorie

[avertist]

Thank you Rilian and Marjorie for the recommendations. :)