"Precisely because we are Christians, we are called to seek and implement paths towards reconciliation and peace."
"In this regard we also express our hope for a peaceful resolution of the issues surrounding Nagorno-Karabakh," a landlocked region in nearby Azerbaijan which has seen ongoing conflict over the past century.
The letter went on to call on the faithful of both Churches to follow Christ's teaching, and "to open their hearts and hands to the victims of war and terrorism, to refugees and their families."
"At issue is the very sense of our humanity, our solidarity, compassion and generosity, which can only be properly expressed in an immediate practical commitment of resources," the declaration reads.
The letter calls on political leaders and the international community to do more in ensuring "the right of all to live in peace and security, to uphold the rule of law, to protect religious and ethnic
minorities, to combat human trafficking and smuggling."
Amid the divisions seen among Christians, "what unites us is much more than what divides us," and "this is the solid basis upon which the unity of Christ's Church will be made manifest," the declaration said.
The joint declaration addressed the role of secularism in feeding the crisis in the family as witnessed worldwide.
"The secularization of large sectors of society, its alienation from the spiritual and divine, leads inevitably to a desacralized and materialistic vision of man and the human family. In this respect we are concerned about the crisis of the family in many countries," the letter reads.
"The Armenian Apostolic Church and the Catholic Church share the same vision of the family, based on marriage, an act of freely given and faithful love between man and woman."
The letter acknowledged the successful "new phase" in relations between the Armenian Apostolic Church and the Catholic Church, "strengthened by our mutual prayers and joint efforts in overcoming contemporary challenges."
"Today we are convinced of the crucial importance of furthering this relationship, engaging in deeper and more decisive collaboration not only in the area of theology, but also in prayer and active cooperation on the level of the local communities, with a view to sharing full communion and concrete expressions of unity."
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"The path of reconciliation and brotherhood lies open before us. May the Holy Spirit, who guides us into all truth, sustain every genuine effort to build bridges of love and communion between us."
Pope Francis' June 24-26 to Armenia was organized following the invitation of Karekin II, the nation's civil authorities, and the Catholic Church.
The visit also comes a little over 100 years after the 1915 Armenian genocide, during which some 1.5 million Christians were killed by the Ottoman Empire, and millions more displaced.
Armenia has an ancient Christian legacy, being the first nation to adopt Christianity as a state religion, in 301.