Conflict and violence in the world will never end if people do not fully understand their responsibility to each other as members of one human family, Pope Francis said in a written message.

"In light of this, the Christian churches, together with other religious traditions, have a primary duty to offer an example of dialogue, mutual respect and practical cooperation," he said in the message to Ecumenical Patriarch Bartholomew of Constantinople.

"With profound gratitude to God, I have experienced this fraternity at first hand in the various encounters we have shared," he told the Orthodox patriarch.

Cardinal Kurt Koch, president of the Pontifical Council for Promoting Christian Unity, delivered the message to the patriarch in Istanbul Nov. 30 during services to mark the feast of St. Andrew the Apostle, the patriarchate's patron saint. The cardinal led a Vatican delegation to Istanbul to take part in the Divine Liturgy presided over by the patriarch.

St. Andrew's charity, apostolic zeal and perseverance are a "source of encouragement in these difficult and critical times," the pope said.

"Giving glory to God also strengthens our faith and hope in the one who welcomed into eternal life the holy martyr Andrew, whose faith endured in time of trial," he said.

The world is facing numerous trials right now, the pope said. "Together with the challenges posed by the current pandemic, war continues to afflict many parts of the world, while new armed conflicts emerge to steal the lives of countless men and women."

The many efforts by national and international entities to promote peace "are useful and necessary, yet conflict and violence will never cease until all people reach a deeper awareness that they have a mutual responsibility as brothers and sisters," he said.

With this in mind, he said, religious leaders have an important responsibility to offer the world a good example.

Pope Francis expressed his gratitude for the strengthened relations between the Catholic Church and the Ecumenical patriarchate, "even as we continue to yearn for the goal of the restoration of full communion expressed through participation at the same eucharistic altar."

"Although obstacles remain, I am confident that by walking together in mutual love and pursuing theological dialogue, we will reach that goal," he said.