In the third apostolic exhortation of his pontificate, Pope Francis issued a warning to Catholics who criticize his calls for countries to welcome migrants who “risk their lives to offer a future to their children.”

In Monday’s much-awaited apostolic exhortation — which guides Catholics regarding ways to strive for “holiness” — Francis, 81, continued his advocacy for the plight of people fleeing war, persecution and poverty, despite the current anti-migrant sentiment in many parts of the world, Yahoo reported.

“Some Catholics consider the situation of migrants to be a secondary issue,” Francis wrote. “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.”

Francis cited a passage from the Old Testament urging the welcoming of foreigners, noting that the issue was not “a notion invented by some pope, or a momentary fad.”

In the beginning of Francis’ five-year papacy, he uttered strong words against governments, which he contended had not done enough to welcome millions of refugees and migrants fleeing their home countries.

Over time, Francis moderated his tone on the issue, suggesting that host countries have the right to regulate the number of arrivals according to their capacity to accommodate and integrate foreigners.

“There are those who feel encouraged by the pope’s stance on migrants and it is still a majority,” said Christophe Dufour, archbishop of the French city of Aix-en-Provence. “And there is a small number who say, ‘he is naive, let him come and live among migrants, it is not so simple.'”

The exhortation, titled “Gaudete et exsultate” (Rejoice and be glad), also included the reiteration of Francis’ staunch opposition to abortion.

“Our defence of the innocent unborn needs to be clear, firm and passionate,” Francis said, adding that the “lives of the poor” were “equally sacred.”

The New York Times further reported on the Pope’s push to elevate the migrant issue:

“The other harmful ideological error is found in those who find suspect the social engagement of others, seeing it as superficial, worldly, secular, materialist, communist or populist,” Pope Francis wrote in an apostolic exhortation on the subject of holiness issued Monday morning. “Our defense of the innocent unborn, for example, needs to be clear, firm and passionate. Equally sacred, however, are the lives of the poor, those already born, the destitute, the abandoned.”

The pope’s vision of holiness explicitly highlights migrants, whose plight he has sought to elevate to global attention perhaps more than any other issue.

“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,” he said.“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,” he continued, adding that welcoming the stranger at the door was fundamental to the faith. “This is not a notion invented by some Pope, or a momentary fad.”