Having faith does not mean there will be no difficulties in life, either for individuals or for the church as a whole, Pope Francis said, but it does mean knowing that Jesus is there to give courage and to defeat evil.

"The Lord knows that the boat of our life, as well as the boat of the church, is threatened by headwinds, and that the sea on which we sail is often turbulent," the pope said Aug. 13, commenting on the day's Gospel story about Jesus walking on the water toward the disciples whose boat was being tossed about by the wind.

Jesus "does not spare us the hard work of sailing," the pope told an estimated 15,000 people gathered in the square for the midday recitation of the Angelus. Instead, "he invites us to face difficulties so they too might become salvific places, so Jesus can conquer them, so they become opportunities to meet him."

"In our moments of darkness, he comes to meet us, asking to be welcomed like that night on the lake" when the disciples were afraid until Jesus reassured them, Pope Francis said.

In biblical times, people thought that large expanses of water were "the haunts of evil powers that man was not able to master," symbols of chaos and darkness, he said. The disciples probably were not just afraid of sinking but also of being "sucked in by evil."

"And here comes Jesus, walking on the waters, that is, over the powers of evil," telling the disciples not to be afraid, the pope said.

"By walking on the water, he wants to say, 'Do not be afraid. I put your enemies under my feet' -- a beautiful message -- 'I put your enemies under my feet' -- not people! -- not that kind of enemy, but death, sin, the devil -- these are the enemies of the people, our enemies," Pope Francis said. "Jesus tramples on these enemies for us."

In the Gospel story, Peter gets out of the boat and starts walking on the water toward Jesus, but then gets frightened and starts to sink.

Peter cries out, "Lord, save me!" which Pope Francis said is a "beautiful" prayer that "expresses the certainty that the Lord can save us, that he conquers our evil and our fears."

Pope Francis asked the people in the square to repeat that prayer together three times: "Lord, save me! Lord, save me! Lord, save me!"