His Holiness Patriarch Kirill of Moscow and All Rus' addressed the archpastors, pastors, deacons, monastics and all faithful children of the Russian Orthodox Church in connection with the celebration of the 1700th anniversary of the First Ecumenical Council.

On May 26, 2025, Monday of the 6th week after Easter, on National Memorial Day, at St. Tikhon's Monastery in Pennsylvania, the hierarchs, clergy, and laity of the Orthodox Church in America and the parishes of the Moscow Patriarchate in the United States prayerfully celebrated the 100th anniversary of the death of the founder of the monastery, St. Tikhon (Belavin), Patriarch of Moscow and All Rus', as well as the 55th anniversary of the autocephaly of the Orthodox Church in America and the establishment of the Patriarchal Parishes in the United States.

On May 24, 2025, Saturday of the 5th week after Easter, the day of remembrance of the Equal-to-the-Apostles Methodius and Cyril, in the Church of the Three Hierarchs in Garfield, New Jersey, the participants of the XV Congress of the Clergy and Laity of the Parishes of the Moscow Patriarchate in the USA, headed by the temporary Administrator of the Patriarchal Parishes in the USA and Canada, Bishop Matthew of Sourozh, jointly honored the memory of the Holy Teachers of the Slavs and the 100th anniversary of the death of St. Tikhon, Patriarch of Moscow. The ark with a particle of his holy relics was brought to the church by Bishop Matthew at the beginning of the service.

On the evening of May 23, 2025, on the eve of the day of remembrance of the holy equal-to-the-apostles Methodius and Cyril, teachers of the Slavs, after the end of the first day of the XV Congress of Clergy and Laity, its participants gathered in the Peter and Paul Cathedral in Passaic for prayer at the Great Vespers, which was led by the temporary Administrator of the Patriarchal Parishes in the USA, Bishop Matthew of Sourozh. The Bishop was assisted by members of the Episcopal Council in holy orders, deans of the districts and the clergy of the cathedral. Before the beginning of the service, a reliquary with a particle of the relics of St. Patriarch Tikhon was brought into the church.

On May 23, 2025, in the parish center of the Peter and Paul Cathedral in Passaic, New Jersey, under the chairmanship of the temporary Administrator of the Patriarchal Parishes in the USA and Canada, Bishop Matthew of Sourozh, the opening of the XV Congress of the Clergy and Laity of the Patriarchal Parishes in the USA took place. It was dedicated to the 100th anniversary of the death of the enlightener of America, Saint Tikhon, Patriarch of Moscow and All Rus', as well as the 55th anniversary of the granting of autocephaly to the Orthodox Church in America and the establishment of the Patriarchal Parishes in the United States of America.

XV Assembly of Clergy and Laity of the Patriarchal Parishes of the Moscow Patriarchate in the USA, held on May 23–24, 2025, sent a greeting address to its Ruling Hierarch — His Holiness Patriarch KIRILL of Moscow and All Rus’ — on the occasion of his Name Day.

On May 22, 2025, on the feast of the transfer of the relics of Saint Nicholas the Wonderworker from Myra in Lycia to Bari, Bishop Matthew of Sourozh, Temporary Administrator of the Patriarchal Parishes in the USA and Canada, celebrated the Divine Liturgy at Saint Nicholas Patriarchal Cathedral in New York City.

On the evening of May 21, 2025, on the eve of the celebration of the transfer of the relics of St. Nicholas the Wonderworker from Myra in Lycia to Bari, Bishop Matthew of Sourozh, Temporary Administrator of the Patriarchal Parishes in the USA and Canada, celebrated an all-night vigil at St. Nicholas Patriarchal Cathedral in New York City.

On May 21, 2025, Bishop Matthew of Sourozh, Acting Administrator of the Patriarchal Parishes in the USA and Canada, held a working meeting at the Moscow Patriarchate Representation in New York with members of the organizing committee for the preparation of the Congress of Clergy and Laity, which will take place on May 23-24, 2025, at the parish center of Sts. Peter and Paul Cathedral in Passaic, New Jersey.