The Entrance Antiphon today contains one of the last promises of Jesus before the Ascension. It the promise of the Holy Spirit coming upon the disciples and consequently upon the whole Church, and granting us the power and strength we need for the mission which Jesus entrusts to us: "You will be my witnesses to all the world."

Matthew's Gospel formulates this mission in slightly different terms. "Make disciples of all the nations." As expressed in this verse from Acts, Jesus' words constitute both command and promise. He orders us to be witnesses to the whole world and, at the same time, promises us that we shall indeed be such witnesses. Every command we receive from Jesus, by its very nature, is also a promise of the grace and strength necessary to obey the command, for without Jesus, without God's grace, we can do nothing.

In the Opening Prayer for today's Mass, we repeat Jesus' words and ask for the power of the Holy Spirit to keep us faithful and to do God's will in our daily lives. Our prayer is a compelling reminder that we cannot be witnesses to Jesus and His Gospel unless we are faithful and trustworthy companions of Jesus.