The determinant difference between the Holy Fathers and ordinary ecclesiastic authors is the sanctity of the formers' lives and their sense of pastoral responsibility. This sense of pastoral responsibility of the Fathers is precisely the proof of their true and guileless love, which is expressed, not only towards the faithful in order that they remain in the proper faith, but is also extended towards heretics - even if expressed with austerity by forbidding common prayer - so that they might be brought to the realization that they are outside the Church, and to thereafter return in repentance to whatever the ancient Church teaches and be saved.
The distorting of the spirit of the sacred Canons shows just how much "the Spirit vivifies, whereas the letter destroys". The meticulous endeavour to shroud the attempted misinterpretation of the sacred Canons by acknowledging the point in question - that is, the imposition of common prayers - cannot remain hidden. Both the letter and the spirit of the sacred Canons explicitly forbid common prayers. Hence, the intentions of the aforementioned teacher are obvious: to encourage the Orthodox to pray together with heretics, and to avert predictable reactions by the faithful. He furthermore wants to influence decision-making - normally a product of unbiased discussions in the Holy Spirit - thus trying to impose his own personal opinions and views. In that attempt, the Holy Fathers have been scorned.
Saint Nicodemus of the Holy Mountain - a renowned interpreter of the sacred Canons - has thus been underestimated; he has additionally been accused of supposedly hating heretics, in the attempt to demote his objectivity and undermine the authority of his words. Saint Nicodemus' words are absolutely clear: "So, if those who are Catechumens are not excused to remain in place during the commencement of the Divine Liturgy, how can heretics?".
Another important Canonologist, Theodore Valsamon, is considered a debatable case, because his interpretation does not seem to agree with his theories. "The sacred Canons do not constitute the expression of some legalistic spirit - which tends to render everything legalistic and confines the life of the spirit to legalistic formulas - but rather (they constitute) the expression of the pastoral care of the Church for the salvation of Her members.
The Divine Liturgy is the capital of the Orthodox dogmas, the summary of the entirety of divine Providence, the heart of the Church, the center of Orthodox worship, the source of Orthodox spirituality and the seal of Orthodoxy's entire life. It is the Mystery of Mysteries, where the Canonical order and Tradition of the Church keep the uninitiated at a distance, and want only the faithful to participate and to approach it "with a fear of God, faith and love".
The golden mouth of the Church warns: "Let no-one commune with the non-pupils... I would first leave my soul, rather than undeservingly impart the Majestic Blood". One can discern here the pastoral responsibility displayed by the Hierarch, in order to subsequently perceive how thoughtlessly (and lacking in theological sensitivity) certain laypeople propagandize, but also how certain "theologizing" Orthodox clergymen encourage common prayers with the heterodox, without the necessary precedent unity - in the Faith and in the Communion of the Holy Spirit.
The faithful populace preserves its Faith sensor orthodox, and its criterion of Orthodoxy fully developed and perceptive. It will never accept - much less tolerate - any novel interpretations in the topics of Dogma and Ethos, which it rightly regards as interlinked and unalterable.
 a) fr. Anastasios Gotsopoulos, (An approach to the canonical praxis of the Church), "One must not pray with heretics or schismatics", Patrae, 2008.
b) Archmandrite Kyr. Kostopoulos, (The anti-canonicity of common prayer with heretics), Patrae 2008.
 The Rudder (Pedalion), page 670.
 Archmandrite George Kapsanis (The Poemantic Ministry according to the sacred Canons), Piraeus, 1976, page 59.
 On the Gospel according to Matthew, 82, EPE 12, 220.