Spiritual leader of more than four million Ukrainian Greek Catholics worldwide, Major Archbishop Sviatoslav Shevchuk describes his role in familial terms.

“My mission is to be a father to them, to assure them the church of Kiev takes care of them — a church that is reestablishing its own existence in the capital of Ukraine, yet is a global church,” he says, sitting in a conference room beside the modernistic, towering Cathedral of the Resurrection of Christ in the Ukrainian capital of Kiev.

Greek Catholics comprise nearly 9 percent of Ukraine’s population, about four million people, the majority of whom live in western Ukraine. Yet Ukrainian Greek Catholic parishes also flourish in Argentina, Australia, Brazil, Canada and the United States; smaller communities may also be found in China and the United Arab Emirates.

From 1946 until 1990, those Ukrainian Greek Catholics living in the “diaspora” tenaciously maintained their faith even as the Soviets had eliminated their church back home. This resolve, this loyalty to uphold their identity, Archbishop Sviatoslav says, helped them to remain true “to their faith and to their Christian traditions.”

These traditions are steeped in the Byzantine customs of the ancient church of Constantinople, from which they received the faith when the grand prince of the Rus’, Vladimir of Kiev, accepted Christianity in its Byzantine form and instructed his subjects to be baptized in the year 988.

Growing up in the western Soviet Ukrainian region of Lviv, the 46-year-old prelate says, he had not expected to become a priest, let alone a bishop or the head of a church then in hiding. But he discovered his faith in the underground, where hundreds of thousands of people risked their lives on a daily basis to maintain their Greek Catholic faith in defiance of government suppression. Their hope and strength of will empowered the church to carry on, the major archbishop adds.

But he learned the true nature of sacrifice after joining an underground seminary: “I was taught that being a priest means to offer not only bread and wine, not only the blood and body of Christ, but to offer your own blood and your own flesh.”

When Ukraine achieved its independence in 1991, about 300 priests surfaced from hiding to serve the needs of a faith community reeling from oppression and poverty. They now number more than 3,000 nationwide, an example of what the archbishop calls an “explosion and resurrection” of the Greek Catholic Church, which has emerged as a pillar of the Ukrainian nation.

Despite its deep connection with Ukraine, the church is a Catholic faith community that transcends borders and peoples. Tasked with balancing these regional and global identities, the archbishop often references Pope John Paul II’s call for Catholics to breathe with the “two lungs” of Western and Eastern traditions.

“The Catholic Church is a globally rich community with different traditions, different rites,” he says of the 23 Catholic Eastern churches that include some 18 million members. “It’s not only important to have those two lungs — Western and Eastern — but to breathe with them fully.”

When Pope Benedict XVI confirmed his election as major archbishop by the Holy Synod of the Ukrainian Greek Catholic Church in March 2011, Archbishop Sviatoslav found himself in an intermediary role between the Orthodox East and Catholic West. He describes this role as a “special vocation … to witness the unity of the church of Christ.” Catholics, he adds, believe the successor of St. Peter, as a bridge builder, is a visible sign from Christ. Aiding in this vocation is Archbishop Sviatoslav’s relationship with Pope Francis, who as the archbishop of Buenos Aires had mentored him when he was named bishop in Buenos Aires in 2009 — the youngest Catholic bishop in the world, at that time.

Yet current circumstances also present grave challenges. The ongoing war in Ukraine’s east has stoked tensions along ethnic, linguistic, national and even religious lines, despite the common heritage the churches of Ukraine and Russia share in Constantinople.

“These are very difficult, painful situations,” the archbishop says, adding that to promote his “message of reconciliation,” the Greek Catholic Church regularly holds services to pray for the intentions of all those affected, including “those who consider us their enemies.”

“We have to stop the war. We have to do everything to prevent further escalation of that aggression. We have to stop bloodshed between our nations.”

The urgency of this mission has also brought his church closer to other Eastern churches, such as those of Syria and Iraq. “We cooperate and share our thoughts, our experiences — how to serve this new, difficult world, especially in conditions of war,” he says. “We have much in common.”

Witness, he stresses, remains a crucial task for Christians.

“We’re supposed to express our solidarity with those who suffer, and it’s important to be a voice for those nations who are now under direct aggression.” By the same measure, what is happening in Ukraine, he emphasizes, must not be a “forgotten, silent war.”

And solidarity, Archbishop Sviatoslav adds, is but one of the four core values of the church’s social teaching. “Dignity, the common good, solidarity and subsidiarity, this is the common ground of ecumenical social action.”

In accordance with his mission, Archbishop Sviatoslav must keep a keen eye fixed on such commonalities all Christians share.

“They have the same sins, the same hopes, the same anxieties, but also all have the same need for joy and hope of Christian life.”

Mark Raczkiewycz is editor at large for the Kyiv Post in Ukraine. His work has appeared in the The Financial Times, The Irish Times and Jane’s Intelligence, among other places.