"Then, in discouragement, we give up on mercy," he continued. "But the Lord challenges us: 'Don't you believe that my mercy is greater than your misery? Are you a backslider? Then be a backslider in asking for mercy, and we will see who comes out on top.'"
When we fall into the same sin again and again, we may experience great sorrow, but even this sorrow is beneficial, because it "slowly detaches us from sin," he said.
Thirdly, another "closed door" we may put up to keep ourselves from confession is not wanting to forgive ourselves, the pope said. Someone who has committed a grave sin may think that if they cannot, or do not want to, forgive themselves, how could God want to forgive them?
"This door, however, is only closed on one side, our own; but for God, no door is ever completely closed," he said.
"As the Gospel tells us, he loves to enter precisely 'through closed doors,' when every entrance seems barred. There God works his wonders. He never chooses to abandon us; we are the ones who keep him out."
"Let us today, like Thomas, implore the grace to acknowledge our God: to find in his forgiveness our joy, and in his mercy our hope," he said.
Following the Mass, Pope Francis led the faithful in praying the customary Regina Coeli prayer. In his brief message before the prayer, the pope thanked all the Missionaries of Mercy gathered in Rome for their meetings.
He also wished a happy Easter to those who are members of the Orthodox Church and are thus celebrating Easter today. "May the Risen Lord fill them with light and peace, and comfort the communities that live in particularly difficult situations," he said.
Francis also denounced the use of chemical bombs, following an attack in Douma, Syria that killed over 40 men, women, and children, saying, "there is no such thing as a good war or a bad war. Nothing justifies the use of such bombs."
Hannah Brockhaus is Catholic News Agency's senior Rome correspondent. She grew up in Omaha, Nebraska, and has a degree in English from Truman State University in Missouri.