Man's Call To Salvation

We listen to the readings from the Bible. the readings remind us of God's saving love and of His promise to send a Messiah. They also remind us of all the good things God has done for us. We respond by singing psalms about God.
The Apostles must have been sad and frightened after the death of Jesus. To forget their sadness and fear, they must have exchanged stories about things Jesus told them in the past. They must have sung psalms, too; to keep their spirits up.