Well, if we can all play ...
"Another thing the blessed man taught and insisted upon with all was never on any occasion whatsoever to associate with heretics and, above all, never to take the Holy Communion with them, 'even if', the blessed man said, 'you remain without communicating all your life, if through stress of circumstances you cannot find a community of the catholic Church. For if, having legally married a wife in this world of the flesh, we are forbidden by God and by the laws to desert her and be united to another woman, even though we have to spend a long time separated from her in a distant country, and shall incur punishment if we violate our vows, how then shall we, who have been joined to God through the Orthodox faith and the catholic Church -- as the apostle says: "I espoused you to one husband that I might present you as a pure virgin to Christ" (2 Cor. 11:2) -- how shall we escape from sharing in that punishment which in the world to come awaits heretics, if we defile the orthodox and holy faith by adulterous communion with heretics?'
For 'communion', he said, 'has been so called because he who has "communion" has things in common and agrees with those with whom he has "communion". Therefore I implore you earnestly, children, never to go near the oratories of the heretics in order to communicate there.'"
-St. John the Almsgiver, Patriarch of Alexandria (7th Century AD)
[Three Byzantine Saints, "The Life of Saint John the Almsgiver",
Translators: Elizabeth Dawes & Norman H. Baynes,
St. Vladimir's Seminary Press, Crestwood: 1977; p. 251]
"With all our strength let us beware lest we receive Communion from or give it to heretics. 'Give not what is holy to the dogs,' says the Lord. 'Neither cast ye your pearls before swine', lest we become partakers in their dishonour and condemnation."
- St. John of Damascus [An Exact Exposition of the Orthodox Faith, IV, 13]
“Even if one should give away all his possessions in the world, and yet be in communion with heresy, he cannot be a friend of God, but is rather an enemy.”
- St. Theodore the Studite
(PG 99, 1205)
“Chrysostomos loudly declares not only heretics, but also those who have communion with them, to be enemies of God.”
- St. Theodore the Studite
[Epistle to Abbot Theophilus]
“Guard yourselves from soul-destroying heresy, communion with which is alienation from Christ.”
-St. Theodore the Studite
[P.G. 99.1216.]
“The heretics were totally shipwrecked with regard to the Faith; but as for the others, even if in their thinking they did not founder, nevertheless, because of their communion with heresy they are perishing.”
- St. Theodore the Studite
[Patrologia Graeca 99, 1164]