I present this quote from Fr Seraphim Rose that is found at the bottom of the St Mark's Sermon at the link in the article:
- The "Latin Chapter" to which St. Mark replies are those written by Julian Cardinal Cesarini (Russian translation in Pogodin, pp. 50-57), giving the Latin teaching, defined at the earlier "Union" Council of Lyons (1270), on the state of souls after death. This teaching strikes the Orthodox reader (as indeed it struck St. Mark) as one of an entirely too "literalistic" and "legalistic" character. The Latins by this time had come to regard heaven and hell as somehow "finished" and "absolute," and those in them as already possessing the fullness of the state they will have after the Last Judgment; thus, there is no need to pray for those in heaven (whose lot is already perfect) or those in hell (for they can never be delivered or cleansed from sin). But since many of the faithful die in a "middle" state—not perfect enough for heaven, but not evil enough for hell—the logic of the Latin arguments required a third place of cleansing (purgatory"), where even those whose sins had already been forgiven had to be punished or give "satisfaction" for their sins before being sufficiently cleansed to enter heaven. These legalistic arguments of a purely human "justice" (which actually deny God's supreme goodness and love of mankind) the Latins proceeded to support by literalistic interpretations of certain Patristic texts and various visions; almost all of these interpretations are quite contrived and arbitrary, because not even the ancient Latin Fathers spoke of such a place as "purgatory," but only of the "cleansing" from sins after death, which some of them referred to (probably allegorically) as by "fire."
- In the Orthodox doctrine, on the other hand, which St. Mark teaches, the faithful who have died with small sins unconfessed, or who have not brought forth fruits of repentance for sins they have confessed, are cleansed of these sins either in the trial of death itself with its fear, or after death, when they are confined (but not permanently) in hell, by the prayers and Liturgies of the Church and good deeds performed for them by the faithful. Even sinners destined for eternal torment can be given a certain relief from their torment in hell by these means also. There is no fire tormenting sinners now, however, either in hell (for the eternal fire will begin to torment them only after the Last Judgment), or much less in any third place like "purgatory"; all visions of fire which are seen by men are as it were images or prophecies of what will be in the future age. All forgiveness of sins after death comes solely from the goodness of God, which extends even to those in hell, with the cooperation of the prayers of men, and no "payment" or "satisfaction" is due for sins which have been forgiven. 
Concerning the "satisfaction theory" of purgatory this is only one model. Another model is about dealing with the lasting effects of sins such as passions, worldly attachments, addictions, mental obsessions, and depressions. These things can inhibit our spiritual progress and retard our love of God. How are these things dealt with after death if they haven't been "purified" before death? St John of Damascus hints at it, and in fact Fr Seraphim tells us in the next paragraph:
- . . .the faithful who have died with small sins unconfessed, or who have not brought forth fruits of repentance for sins they have confessed, are cleansed of these sins either in the trial of death itself with its fear, or after death, when they are confined (but not permanently) in hell, by the prayers and Liturgies of the Church and good deeds performed for them by the faithful.
I propose that this is the proper definition of Purgatory from an Orthodox perspective. All talk of "No, Orthodox Christians do not believe in Purgatory." are unhelpful and equivocating seeing as we do believe in a process of purification after death for the faithful departed that can be assisted by the prayers and good works of the living.
There are specific differences in emphasis between the EOC and RCC and it is true that Orthodox teachers strongly disagreed with specific theories and interpretations of Purgatory, but not in the overall doctrine. Insistence against Purgatory in an unclear manner only helps protestantize the True Faith as we jettison legitimate Apostolic Teachings because we "think" they are "too catholic." The end result of this rejection may be the organic cultural rejection of prayers for the dead as the next generation of Orthodox Christians may see no need for it.