During his weekly general audience on Wednesday, Pope Francis said everyone is "required" to welcome migrants.
World Refugee Day on June 20 should be "an occasion to turn an attentive and fraternal gaze to all those who are compelled to flee their homes in search of peace and security," the pontiff said in St. Peter's Square.
"We are all required to welcome, promote, accompany, and integrate those who knock on our doors," Francis said. "I pray that states will strive to ensure humane conditions for refugees and to facilitate integration processes."
The care of migrants is a familiar theme for Francis, who has frequently championed immigration throughout his 11-year pontificate and called on Christians to treat the issue as a primary concern.
Francis cited the example of Jesus commanding his disciples to welcome strangers in his 2018 apostolic exhortation "Gaudete et Exsultate," or "Rejoice and Be Glad."
"We often hear it said that, with respect to relativism and the flaws of our present world, the situation of migrants, for example, is a lesser issue," the pontiff wrote. "Some Catholics consider it a secondary issue compared to the 'grave' bioethical questions.
"That a politician looking for votes might say such a thing is understandable, but not a Christian, for whom the only proper attitude is to stand in the shoes of those brothers and sisters of ours who risk their lives to offer a future to their children. Can we not realize that this is exactly what Jesus demands of us, when he tells us that in welcoming the stranger we welcome him?"
Francis also defended his ideas on immigration as a central tenet of the Bible and not merely a pet cause.
"This is not a notion invented by some Pope, or a momentary fad," he wrote. "In today's world too, we are called to follow the path of spiritual wisdom proposed by the prophet Isaiah to show what is pleasing to God."
In his advanced release message for the World Day of Migrants and Refugees on Sept. 29, Francis pushed the immigration message even further, writing that the Israelites' journey in the biblical narrative of Exodus "naturally comes to mind" when thinking about migrants now.
"[I]t is possible to see in the migrants of our time, as in those of every age, a living image of God's people on their way to the eternal homeland," he wrote. "Their journeys of hope remind us that 'our citizenship is in heaven, and it is from there that we are expecting a Saviour, the Lord Jesus Christ' (Phil 3:20)."