During the Angelus on World Mission Day, the pope reflected on the figure of Paul the Apostle.
He was one of the great evangelizers of the early Church and the pope recommended that people imitate his example.
"Today is a time of mission and a time of courage! Courage to strengthen our faltering steps, to commit ourselves to the Gospel, to regain confidence in the strength that mission brings with itself."
Pope Francis asked Catholics to be courageous to speak of God without imposing on others, but with fidelity to His message.
"We are asked to be courageous, to offer the world an alternative without being controversial or aggressive. We are asked to be courageous to open up to everyone, but to never diminish the absoluteness and unity of Christ, the true Savior of all."
The pope concluded the Angelus making a dramatic appeal for peace in Mosul and all over Iraq, amid reports that the Islamic state is using boys as human shields to stop the attacks.