The Pope explained that Christians' strength in prayer comes from God alone.
"In our daily journey, especially in difficulties, in the struggle against evil outside of ourselves and within us, the Lord is not far way, he is at our side; we fight with him beside us, and our weapon is prayer, which makes us feel his presence alongside of us, his mercy, even his help," Pope Francis said.
The Pope acknowledged the ""struggle to carry on every day," adding "God is our ally, faith in him is our strength, and prayer is the expression of this faith."
"If the faith goes out, if prayer goes out, and we walk in the darkness, we will be lost on the journey of life," he added.
The Pope reflected on Sunday's gospel story of the "persistent widow" who refused to give up asking a judge to render a just verdict. At the end, she convinces him to grant her justice.
"We can therefore learn from this widow in the gospel," said Pope Francis. "She was good, this widow. She knew to fight for her children."