Christians in pursuit of unity should not be afraid to broach potential areas of disagreement such as marriage, family, and sexuality, Pope Francis said in a meeting with the head of Sweden's Lutheran church.

"All Catholic faithful" are invited "to take up, recognize the signs of the times, the way of unity for overcoming divisions among Christians," the pontiff said during the private audience with Lutheran archbishop Uppsala Antje Jackelen.

Division, he said – speaking in reference to the Vatican II decree on ecumenism, Unitatis Redintegratio – is not only in opposition "to the will of Christ, but is also a scandal to the world and causes damage to the holiest of causes: the preaching of the Gospel to every creature."

During the May 4 private audience at the Vatican, the Pope stressed that unity should be compelled by charity toward those suffering from poverty and violence, and those in need of mercy.

"Especially the witness of our persecuted brothers and sisters pushes us toward fraternal communion," he said.

Pope Francis also warned against the avoidance of relevant issues today in the name of ecumenism. Topics, such as the respect for the dignity of the human person, or those pertaining "to the family, marriage, and sexuality," he said, "cannot be silenced or ignored out of fear of putting the already established ecumenical consensus into jeopardy."

"It would be a shame if, in these important matters, new denominational differences were strengthened."

In the area of promoting unity of Catholics and Lutherans, such as in "visible unity in faith" and sacramental life, there is still much to be done, the Pope said.

However: "We can be certain that the Spirit Paraclete will always be light and strength for spiritual ecumenism and theological dialogue."

The pontiff also acknowledged the upcoming anniversary of the Reformation in 2017, as well as the joint document "From Conflict to Communion" published by the Lutheran-Catholic commission for unity.

He expressed his hope that this initiative would encourage further steps toward unity, with God's help, "and our collaboration with Him and one another."

Born in Germany, Jackelen is the first female head of the Lutheran church in Sweden, and the nation's first foreign archbishop since the 12th century.