The first reading clearly shows that something stupendous happened to our fathers in faith on Pentecost—so stupendous that it changed the rest of their lives. After the Ascension the apostles spent much of their time working and wondering what to do. They had no compelling mission, only the memory of Jesus recently departed. They did not yet have the personal and intense conviction that Christ lives and lived in them.
Together again on Pentecost they were suddenly filled with the Holy Spirit. In an instant they were filled with the conviction that Jesus lived in them, had given them a message and a mission. Now with their hearts on fire, they burst upon Jerusalem and, later, the world with the message of Jesus Christ.
Such an experience, though unique, is mirrored in smaller ways in the lives of all of us. We experience our own moments of conviction and conversion. Do we realize this? Do we make the most of them?