:"It was natural that in May 1945, immediately after the victorious end of the Great Patriotic War, an Initiative Group for Reunification of the Greek-Catholic Church with the Russian Orthodox Church was formed to implement the idea for which Father Gabriel suffered so much."</ref>
On [[February 23]], 1946, Metr. John of Kiev received Fr. Gabriel and twelve other priests from the Unia to Orthodoxy. By the end of the month two of these priests, Antoni Pelvetsky and Mykhailo Melnyk, had been consecrated bishops. Over the following months additional priests and [[laity|laypeople]] joined Fr. Gabriel's movement. Orthodox scholar Dr. Vladimir Moss has written the following historical-critical account
of the movement and of the council:
<blockquote>"After the Soviet victory in the war, it was the turn of the Soviets and the Sovietized Moscow Patriarchate to apply pressure. Towards the end of the war it was suggested to the uniate episcopate in Western Ukraine that it simply “liquidate itself”. When all five uniate bishops refused, in April, 1945, they were arrested. Within a month a clearly Soviet-inspired “initiative movement” for unification with the MP headed by Protopresbyter G. Kostelnikov appeared. By the spring of 1946 997 out of 1270 uniate priests [78%] in Western Ukraine had joined this movement. On March 8-10 a uniate council of clergy and laity meeting in Lvov [in [[w:St. George's Cathedral, Lviv|St George's Cathedral]]] voted to join the [[Orthodox Church]] and annul the [[Union of Brest|Brest unia]] with the [[Roman Catholic Church]] of 1596. Those uniates who rejected the council were forced underground. Similar liquidations of the uniate churches took place in Czechoslovakia and Romania… Central Committee documents show that the whole procedure was controlled by the first secretary of the Ukrainian party, Nikita Khruschev, who in all significant details sought the sanction of Stalin."<ref>Vladimir Moss. ''[http://www.orthodoxchristianbooks.com/articles/384/orthodoxy-unia-east-central-europe/ Orthodoxy and the Unia in East-Central Europe].'' March 30 / April 12, 2011.</ref></blockquote>
[[Eastern Catholic Churches|Byzantine-Ruthenian Catholic]] priest Christopher Lawrence Zugger argues that Father Gabriel was motivated partly from the hope of saving his son (who, he had been told was a prisoner of the Soviets), partly out of anti-[[Latinization|Latin Catholic]] feelings, and partly out of conviction.<ref>Rev. Christopher Lawrence Zugger. ''"[http://books.google.ca/books?id=HnUnJ7X10BMC&printsec=frontcover#v=onepage&q&f=false The Forgotten: Catholics of the Soviet empire from Lenin through Stalin]."'' Syracuse University Press, 2001. p.423.)</ref> The ''[http://www.encyclopediaofukraine.com/default.asp Encyclopedia of Ukraine]'' adds that Fr. Gabriel's theological position made him a target of NKVD pressure and blackmail during the 1939–41 Soviet occupation of Galicia, when the authorities first tried unsuccessfully to have him organize an ‘away from Rome’ schism in the Ukrainian Catholic church; and when the Soviets reoccupied Galicia in 1944 and arrested the entire Ukrainian Catholic episcopate, he was finally compelled to assume chairmanship of the Initiating Committee for the Reunification of the Greek Catholic Church with the Russian Orthodox Church.<ref name="UKRAINIAN"/>
this religious movement which started with the anti-[[Latinization]] orientation among the Greek Catholic clergy led by Fr. Gabriel, and culminated in the state-sponsored Synod of Lvov, came at the same time that the political atmosphere in the area changed, as the remnants of the Nazi regimes, various nationalistic groups, the Bolshevik forces, and religious differences all collided with the sincerity of the people. In that environment, many of the clergy and laypeople returning to Orthodoxy became victims of fanatics, both religious and political.
On September 20, 1998, in commemoration of the 50th anniversary of the demise of Protopresbyter Gabriel Kostelnik, the [[Divine Liturgy]] was celebrated in St. George’s church, followed by a [[Memorial Services|Panikhida]] at the tomb of Father Gabriel at the [[w:Lychakiv Cemetery|Lychakov cemetery]] conducted by Archbishop Augustine of Lvov and Drogobych.
Later, a historic conference was held on the theme ''‘Protopresbyter Gabriel Kostelnik and His Role in the Revival of Orthodoxy in Galicia’''.<ref name="DECR"/><ref group="note">Taking part in the Divine service and in the conference were hierarchs of the [[Church of Ukraine|Ukrainian Orthodox Church]]: Archbishops Onuphry of Chernigov and Bukovina, Niphont of Lutsk and Volyn, Augustine of Lvov and Drogobych, Sergy of Ternopol and Kremenets, Bishops Methodius of Khust and Vinogradov, Simeon of Vladimir-Volynsky and Koval, representatives of the theological schools from Moscow, Kiev, Lutsk, Pochaev and Warsaw, clergymen from the Rovno, Khust, Chenovtsy; Vladimir-Volynsky and Brest dioceses, Abbess Mikhaila Zaets, mother superior of the Gorodets convent, representatives of the Union of Orthodox Brotherhoods in Ukraine, and many parishioners.</ref> A message from His Holiness Patriarch [[Alexei II (Ridiger) of Moscow|Alexei II]] said that "the death of Protopresbyter Gabriel Kostelnik was an irretrievable loss for the spiritual life of his legacy – the people of God who reunited with Holy Orthodoxy at the Church Council of Lvov and for the Russian Orthodox Church as a whole."<ref name="DECR"/>
Fr. Gabriel has been under consideration for [[glorification]]. According to Archbishop Augustine of Lvov and Galicia, the Church has already begun to work on the appropriate documents.<ref name="Interfax"/><ref group="note">"According to our procedure of canonization, a [[martyr]] really had to suffer for [[Christ]] or for the Church, but not to die by chance. Moreover he shouldn't be a [[heretic]] or a [[schismatic]]. As for the pious, the Reverend Fathers, there should be the sanctity of life and authority. Kostelnik is somewhere in between a martyr and a pious," the Archbishop said.</ref>
<center>''Holy Hieromartyr Gabriel, pray to God for us!''</center>