Archimandrite Parthenios Kelailidis was present in all the Cretan Revolutions from 1858 to 1897. In the Revolution of 1866, he raised the flag and was undoubtedly considered its key figure.

His stay in Trieste and Livorno in Italy, along with his interaction with prominent Greek and Italian politicians, diplomats, legal scholars, and journalists, such as Gregory Ypsilantis, Ioannis Skaltsounis, Robert Galli, Alexander, and Anastasios Byzantios, resulted in him quickly becoming an excellent diplomat, fighting for the rightful demands of the Cretan people and their liberation from Ottoman rule.

At times he believed that the solution to the Cretan Question would be the struggle for the unification of Crete with free Greece, and at other times, the struggle for a form of autonomy as a transitional period until its unification with Greece.

He was elected Bishop of Kissamos and Selino but did not accept his election in order to remain in Italy and from there fight for Crete's freedom.

In addition to his intense national action, Archimandrite Parthenios Kelailidis also had a rich ecclesiastical activity. A dedicated child of the Mother Church, the Ecumenical Patriarchate, he was present in the Metropolitan Issue, fighting so that the Church of Crete would remain an integral part of the Ecumenical Patriarchate.

In the Monastic Issue, he stood by the monasticism of Crete and helped to prevent the closure of the island's monasteries, following the order given by the High Commissioner of the Cretan State, Prince George.

Finally, his conflict with Prince George was enough for him to be persecuted and to find refuge in Athens, where he remained until the end of his life, always by the side of Eleftherios Venizelos.