The opening verses of the Acts of the Apostles pick up the thread of the narrative from the ending of Luke’s first volume (the Gospel of Luke). Both are addressed to Theophilus (Lk 1:3; Acts 1:1), whose name means “beloved of God” or “lover of God.” The symbolic meaning of his name allows every hearer of the Lucan story to her- or himself into the role of the beloved to whom these words are addressed.
Luke resumes the story at the point where Jesus was “taken up.” Like Elijah, who was taken up to heaven in a whirlwind by a fiery chariot (2 Kgs 2:11), and Moses, who was taken up in a cloud at the end of his earthly life (Josephus, Antiquities of the Jews 4.326), so Jesus’ earthly sojourn is ended in the manner of these great figures. Luke narrates the ascension twice: at the conclusion of his first volume (Lk 24:50-53 ) and again at the beginning of the second (Acts 1:9-11 ). In the Gospel, the ascension takes place on Easter Sunday, while Acts speaks of a 40-day period of appearances between the resurrection and ascension. The number 40 is symbolic: Moses spent 40 days on Mount Sinai, and the Israelites wandered 40 years in the desert. Luke uses “40 days” to link the time Jesus spent in preparation for his public ministry after his baptism (Lk 4:1-12 ) with the preparation the disciples undergo before they are “baptized with the Holy Spirit” (Acts 1:5) and begin their public witnessing to the resurrected Christ.
In the Gospel of John—the only other Gospel to mention the ascension (20:17)—the passion, resurrection, ascension, exaltation and giving of the Spirit all describe one moment, not separated in time and space (Jn 19:30; 20:17, 22); in God’s time, all these transformations are instantaneous. Human reality is bound by time and space, and so Luke narrates these mysteries as separate episodes. Luke’s time gaps allow us to reflect on how the mystery unfolds gradually for us, allowing us to be transformed step by step.
In Acts 1:6-8  questions are voiced that the early community needed to have answered in this in-between time. They want to know when will be the parousia and the end-time. They struggle to shift their expectations from a nationalistic messiah who would restore the sovereign reign of Israel, to one who would empower them to be witnesses of the gospel throughout the known world, not only to their own people.
Even though the disciples do not receive all the answers they seek and even though their transformation is incomplete, the ascension marks the point at which they must take up the mission begun by Jesus. There can be no idle looking up at the sky. Rather, as the two angelic messengers affirm, the time has come for them to go forth as witnesses “to the ends of the earth.”