I know many people do not like to use Wikipedia www.en.wikipedia.org/wiki/Sergei_Bulgakov
or Orthodoxwiki www.orthodoxwiki.org/Sergius_Bulgakov
however this presentation is a good synopsis of the Controvery from both:
Bulgakov’s teaching on sophiology is highly controversial. The attempt to understand it properly is hindered by the highly political controversy surrounding it in the 1930s. Ecclesiastical situation in Russian Orthodoxy
It should be noted that by 1931 there existed three separate Russian Orthodox jurisdictions in Europe: the Russian Church Abroad/Sremski Karlovtsy Synod (ROCA or ROCOR) under Met. Antony (Khrapovitsky); the ‘Patriarchal’ Church answering ultimately to Met. Sergius (Stragorodsky) of Moscow (of which the young Vladimir Lossky was a member); and the Russian Church in Western Europe (Bulgakov’s own jurisdiction as well as the church of Georges Florovsky) under Met. Evlogy (Georgievsky) that was under the jurisdiction of the Patriarch of Constantinople -- though in 1934, Met. Evlogy was privately reconciled to Met. Antony, and in 1935 he went to Karlovtsy for a special reunion conference, at which time the schism between him and ROCOR was healed In 1936, Met. Evlogy again cut his ties with ROCOR, quite possibly because of the controversy over "Sophianism". http://orthodoxwiki.org/Sophianism
..Reaction to Bulgakov's writings
In "Decree on Sophianism, 1935". www.orthodoxwiki.org/Sophianism#Decree_of_the_Moscow_Patriarchate
. an ukaz of 24 August, 1935 of Met. Sergius, Bulgakov’s teaching on ‘Sophia’ was described as ‘alien’ to the Orthodox faith. This ukaz was largely based on the epistolary reports of Alexis Stavrovsky. He was also the president of the Brotherhood of St Photius (Alexis Stavrovskii was president; Vladimir Lossky, the vice-president, and Evgraf Kovalevskii <later "Jean-Nectaire (Kovalevsky)". www.orthodoxwiki.org/Jean-Nectaire_(Kovalevsky)_of_Saint-Denis
. of Saint-Denis) were also among the 12-15 young laymen who made up its numbers,whose members had left the jurisdiction of Met. Evlogy for that of Met. Elevthery of Lithuania. This exodus was in reaction to Met. Sergius having removed, on 10 June, 1930, Met. Evlogy as the head of the Russian Orthodox Church in Western Europe (since Met. Evlogy had continually refused to agree to the 30 June, 1927 Declaration of Loyalty to the Soviet government) and named Elevthery as his replacement. In late 1935, Met. Evlogy appointed a commission to look into the charges of heresy levelled against Bulgakov. The commission quickly broke into factions. In June 1936 the majority report (prepared by Vasilii Zenkovskii, Anton Kartashev and others) rejected the charge of heresy but had serious objections about Sophiology. The minority report of 6 July, 1936 was prepared by Fr Sergei Chetverikov and signed by Fr Georges Florovsky, who despite his personal respect for Fr. Sergius, remained an ardent critic of Sophianism for the remainder of his life. Meanwhile, the Church Abroad formally accused Bulgakov of heresy in 1935."The 1935 decision of the Church Abroad".
"The 1935 decision of the Church Abroad". www.orthodoxwiki.org/Sophianism#Decree_of_ROCOR
. was based on Archbishop Seraphim (Sobolev) of Boguchar’s Novoe uchenie o Sofii (Sofia, 1935), as well as on the arguments of St. John (Maximovitch). St. John, in his book The Orthodox Veneration of the Mother of God, discusses at length why the sophianism of Sergius Bulgakov is heresy, specifically one as destructive as Nestorianism. Speaking of those who attempt to deify the Theotokos, he wrote:
"In the words [of Fr. Sergius Bulgakov], when the Holy Spirit came to dwell in the Virgin Mary, she acquired "a dyadic life, human and divine; that is, She was completely deified, because in Her hypostatic being was manifest the living, creative revelation of the Holy Spirit" (Archpriest Sergei Bulgakov, The Unburnt Bush, 1927, p. 154). "She is a perfect manifestation of the Third Hypostasis" (Ibid., p. 175), "a creature, but also no longer a creature" (P. 19 1)....But we can say with the words of St. Epiphanius of Cyprus: "There is an equal harm in both these heresies, both when men demean the Virgin and when, on the contrary, they glorify Her beyond what is proper" (Panarion, Against the Collyridians). This Holy Father accuses those who give Her an almost divine worship: "Let Mary be in honor, but let worship be given to the Lord" (same source). "Although Mary is a chosen vessel, still she was a woman by nature, not to be distinguished at all from others. Although the history of Mary and Tradition relate that it was said to Her father Joachim in the desert, 'Thy wife hath conceived,' still this was done not without marital union and not without the seed of man" (same source). "One should not revere the saints above what is proper, but should revere their Master. Mary is not God, and did not receive a body from heaven, but from the joining of man and woman; and according to the promise, like Isaac, She was prepared to take part in the Divine Economy. But, on the other hand, let none dare foolishly to offend the Holy Virgin" (St. Epiphanius, "Against the Antidikomarionites"). The Orthodox Church, highly exalting the Mother of God in its hymns of praise, does not dare to ascribe to Her that which has not been communicated about Her by Sacred Scripture or Tradition. "Truth is foreign to all overstatements as well as to all understatements. It gives to everything a fitting measure and fitting place" (Bishop Ignatius Brianchaninov)." Fr. Sergei's reply and the episcopal conference, 1937
Bulgakov responded to the heresy accusation in his Dokladnaia zapiska Mitropolitu Evlogiiu prof. prot. Sergiia Bulgakova (Paris, 1936). Archbishop Seraphim then rebutted Bulgakov in his Zashchita sofianskoi eresi (Sofia, 1937). No final report was prepared on the sophiology controversy by the commission set up by Bulgakov’s own jurisdiction. However, Met. Evlogy convoked a bishop’s conference on 26-9 November 1937 to bring closure to the matter. The bishops in their statement were working from reports by Archimandrite Cassian (Bezobrazov) and Chetverikov and they concluded that the accusations of heresy against Bulgakov were unfounded but that his theological opinions showed serious flaws and needed correction.Notes
1. For commentary, texts and a fuller account of the sophiological controversy see Antoine Arjakovsky, Essai sur le père Serge Boulgakov (1871-1944), philosophe et théologien chrétien (Paris: Les Éditions Parole et Silence, 2006), pp. 99-125 and La génération des penseurs religieux de l’émigration Russe: La Revue ‘La Voie’ (Put’), 1925-1940 (Kiev/Paris: L’Esprit et la Lettre, 2002), pp. 433 ff., N. T. Eneeva, Spor o sofiologii v russkom zarubezh’e 1920-1930 godov (Moscow: Institut vseobshchei istorii RAN, 2001), Igumen Gennadii (Eikalovich), Delo prot. Sergiia Bulgakova: Istoricheskaia kanva spora o Sofii (San Francisco: Globus Pub., 1980), Bryn Geffert, ‘Sergii Bulgakov, The Fellowship of St Alban and St Sergius, Intercommunion and Sofiology’, Revolutionary Russia, 17:1 (June 2004), pp.105-41, ‘The Charges of Heresy Against Sergii Bulgakov: The Majority and Minority Reports of Evlogii’s Commission and the Final Report of the Bishops’ Conference’, St Vladimir’s Theological Quarterly, 49.1-2 (2005), pp.47-66 and especially Alexis Klimoff, ‘Georges Florovsky and the Sophiological Controversy’, St Vladimir’s Theological Quarterly, 49.1-2 (2005), pp.67-100.
2. Timothy Ware, The Orthodox Church (London: Penguin Books, 1964); p. 184.
3. Protopresbyter George Grabbe, Toward a History of the Ecclesiastical Divisions Within the Russian Diaspora, in: Living Orthodoxy, Vol. XIV, No. 4, July-August, 1992, pp. 37-39
4. Bulgakov responded to the ukaz in his O Sofii Premudrosti Bozhiei: Ukaz Moskovskoi Patriarkhii i dokladnye zapiski prot. Sergiia Bulgakova Mitropolitu Evlogiiu (Paris: YMCA, 1935), pp. 20-51. Vladimir Lossky then published a well-known critical analysis of Bulgakov’s response to the ukaz as Spor o Sofii (Paris, 1936).
5. Protopresbyter George Grabbe, Toward a History of the Ecclesiastical Divisions Within the Russian Diaspora, In: Living Orthodoxy, Vol. XIV, No. 4, July-August, 1992, p. 38
6. St. John Maximovitch, "The Orthodox Veneration of the Mother of God". www.ortodoks.dk/On_Orthodox_Veneration_of_the_Mary.htm
., (Platina, Ca: St. Herman Press, 1978), p. 40 ff.
It probably should be noted that Father Sergius died in full communion of the Orthodox Church and was not excommunicated despite the controversy of "Sophianism". He was one of the founders of the St. Sergius Orthodox Theological Institute (l'Institut de Théologie Orthodoxe Saint-Serge), in Paris, France. He was the head of this institute and Professor of Dogmatic Theology until his death from throat cancer on July 12, 1944. Read the articles in the notes to get a better understanding of the controversy surrounding Father Sergius and make up your own mind as to the value of his writings.