The first book I wrote, Theophilus, concerned all that Jesus began both to do and to teach, until the day in which he was received up, after he had given commandment through the Holy Spirit to the apostles whom he had chosen.
To these he also showed himself alive after he suffered, by many proofs, appearing to them over a period of forty days and speaking about God’s Kingdom.
Being assembled together with them, he commanded them, “Don’t depart from Jerusalem, but wait for the promise of the Father, which you heard from me.