ROME — Two top cardinals say that as Catholics engage in charity around the world, they must be careful not to put their desire to convert people to their faith ahead of their missionary work.

Speaking at the “Charity will never end” conference organized by the Vatican’s Pontifical Council Cor Unum, an umbrella office to coordinate the Church’s charitable works, Cardinal Antonio Tagle of the Philippines said charity should not be practiced as a way of achieving other ends, “especially proselytism or imposing, even in subtle ways, the Church’s faith on others.”

According to the cardinal, using charitable acts for conversions is “manipulation,” but that doesn’t mean that God should be completely left out of the Church’s missionary work.

“The Christian truth is beautiful,” Tagle said. “And beautiful things attract. So proselytism is imposing, but this good news, beautiful in itself, will attract people without imposing.”

His view was echoed by Cardinal Gerhard Müller, head of the Vatican’s Congregation for the Doctrine of the Faith, who defined proselytism as “a manipulation of the conscience.”

Referring to the ongoing migrant and refugee crisis in Europe, Müller said Christians should be charitable “without hidden intentions.”

“We must not use the charity we practice and transform it into an instrument of proselytism,” Müller said. “An expert Christian knows when it’s time to speak about God and when it’s best to keep quiet. Sometimes a silent witness is the best witness of the love of God.”

He gave the example of his native Germany, where thousands of migrants, many of them Muslims fleeing war and persecution in the Middle East, have been taken in.

“There are among these migrants, the majority of whom are Muslim, who ask, ‘Why are Christians, and not our fellow Muslims, helping us?’”

When these situations arise, he said, aid workers shouldn’t be afraid to give an answer “rooted in the faith.”

Tagle, who spoke at the conference as the head of Caritas Internationalis, a Rome-based federation of 165 Catholic charitable organizations around the world, also said that charity must be given without regard for religious affiliation.

“Instead of relying on partisan politics or ideology, charity operates from a heart that sees a neighbor in any one who is needy,” he said. “Even enemies are to be loved, according to Jesus.”

But he warned that missionary work can’t be done in partnership with organizations that want to make funding conditional on the adoption of abortion and contraception, which Pope Francis has labeled “ideological colonization.”

Tagle defined this as “very complex issue” that requires vigilance and knowledge of the groups, foundations, and agencies with which Catholic charities partner. He also called for aid workers to keep in mind that even though money is important for the Church’s missionary work, “even without funding, we can love, we can serve.”

Pope Francis also addressed the conference, saying that charity means much more than simply donating money to ease one’s conscience. When Catholic aid workers provide material help, he said, those they assist experience God’s concrete love.

“Charity needs to be reflected more and more in the life of the Church,” the pope said. “How I wish that everyone in the Church, every institution, every activity would show that God loves man!”

The “Charity will never end” conference was organized to commemorated the 10-year anniversary of Deus Caritas Est (God is Love), an encyclical letter written by Emeritus Pope Benedict XVI.

Francis said the encyclical touches on a theme that retraces “the entire history of the Church, which is also a history of charity. It is a story of the love received from God, to be carried to the world.”

About 200 people from around the world participated in the conference. The majority of the attendees were Catholic, but there also were representatives of other religions, including Rabbi David Rosen and Prof. Saeed Ahmed Khan of Wayne State University, who reflected on the Muslim view of mercy.