These are reading that were for the feast of the Ascension, which was on Thursday but throughout most of America the feast is moved to Sunday. These are the readings for the Ascension.
We begin every mass in all the Mass Cycles (Year A, B, C) with the beginning of Acts of the Apostles. This is where we learn that Luke is the author of Acts since Theophilus is addressed again and it begins with “In the first book” which is about what Jesus did and taught. Then Jesus told them to wait in Jerusalem for the Spirit to come and you will be my witness throughout the world. With this Jesus was lifted up and the apostles stood there looking up at the sky. The second reading there is an option the one from last year (Year A) or this one it also comes from Paul’s letter to the Ephesians. Paul urges us here to live a life worthy of the call we have received. To some this is a radical idea to live like Christ but there are some people on earth to help us in striving to live like Christ namely the apostles, prophets, evangelists, pastors and teachers. I’ve always taken this reading as we are all to be like Bodhisattva helping each other in trying to live like Christ.
Turning to the Gospel we hear Mark’s account of the Ascension. It comes from the addition to Mark’s Gospel it’s arguably the ending of the gospel some scholars say that the original ending is weird (they did nothing because they were afraid). So we have a typical Mark short and sweet Jesus says “Go out into the world and proclaim the gospel to every creature, baptize those who believe” The apostle could now drive out demons, speak new languages, pick up serpents, and if they drink anything deadly it will not harm them. After Jesus was done saying all this was taken up to heaven and the apostles went forth and preached everywhere and the Lord worked through them. We should follow this call and continue to bring the Gospel out into the world today.