[10] Mykhailo Denysenko was born on 23 January 1929,[11] into a worker's family in the village of Blahodatne in the Amvrosiivsky Raion (district), now in the Donetsk Oblast (province) in Eastern Ukraine.

Filaret was appointed to several diplomatic missions of the Russian Orthodox Church and from 1962 to 1964 served as ROC Bishop of Vienna and Austria.

At that time he also became a permanent member of the Holy Synod, the highest collegiate body of the Russian Orthodox Church, which has the responsibility of electing the Moscow Patriarch.

"[14] On May 3, 1990, Patriarch Pimen of Moscow died and, the same day, Filaret became the locum tenens of the Russian Orthodox Church.

[19] According to internal KGB documents, tasks the KGB assigned Filaret as an agent included promoting Soviet positions and candidates in the World Council of Churches (WCC), the Christian Peace Conference (CPC) and other international bodies, and, by the 1980s, backing the Soviet authorities' attempts to prevent the long-suppressed Ukrainian Catholic Church (disparagingly called 'Uniates') from regaining an open existence, and backing state attempts to prevent religious believers demanding their rights as glasnost and perestroika opened up the sphere of public debate.

[25][26][27] Following Ukraine's declaration of independence from the Soviet Union on 24 August 1991, a national sobor of the Ukrainian Orthodox Church was held from November 1–3.

Filaret convened an assembly at the Kyiv Pechersk Lavra in January 1992 that adopted a request of autocephaly for Ukrainians to the Moscow Patriarch.

[28] In March–April 1992, the Hierarchical Council of the Russian Orthodox Church met with a single agenda item: to consider the resolution passed by the UOC Sobor four months earlier.

[12] On the second day of the meeting, Metropolitan Filaret agreed to submit his resignation to the UOC Synod, and the ROC Synod passed a resolution which stated: "The Council of Bishops took into account the statement of the Most Reverend Filaret, Metropolitan of Kyiv and of All-Ukraine, that for the sake of church peace, at the next Council of Bishops of the Ukrainian Orthodox Church, he will submit a request to be relieved from the position of the Primate of the UOC.

Understanding of the position of Metropolitan Filaret, the Council of Bishops expressed to him its gratitude for the long period of labour as Archbishop of the See of Kyiv and blessed him to carry out his episcopal service in another diocese of the Ukrainian Orthodox Church.

On 14 April, Metropolitan Filaret held a press conference in which he alleged that undue pressure was exerted at the ROC Synod in Moscow, both directly and through threats made by FSK personnel who, he said, were present at the gathering.

On 11 October 2018, the Holy Synod of the Ecumenical Patriarchate of Constantinople announced that Filaret Denisenko, along with the Primate of UAOC, had been "restored to communion with the Church.

[55][56] Volodymyr Burega, Professor and Vice-Rector of the Kyiv Theological Academy, explains this title this way: "in December [2018], no one wanted to aggravate relationships with Patriarch Philaret, since holding the council and receiving the Tomos were at stake.

After the unification council of the OCU, they stated that Filaret was henceforth "honorary patriarch", but what this phrase meant was difficult to understand.

"[57] On 18 December 2018, Filaret's 90th birthday, 23 January 2019, was voted by the Ukrainian parliament as a day of national celebration for the year 2019.

"A conflict erupted between Filaret and Epiphanius because of disagreements concerning the model of governance, the management of the diaspora, the name and the statute of the OCU.

[66] On 5 September 2014, amidst the 2014 Russian military intervention in Ukraine,[67] Filaret held a service to consecrate a memorial cross to the Heavenly Hundred.

[73] Publications such as Church Times, Cogwriter, and Ecumenical News identified Filaret's "new Cain" with Russian President Vladimir Putin.

[68][74][75] Filaret said that the local population in Donbas "must pay for their guilt [in rejecting Kyiv's authority] through suffering and blood".

[80][81][82] In an interview released in March 2020 to the Ukraine Channel 4, he declared that the Holy Eucharist could be administrated from one spoon, because it is impossible to get viruses from the gloriously resurrected Body of Jesus Christ God.