Acts 1:1-5 - The Preface
1 The first narrative I made, O Theophilus, concerning all things that Jesus began both to do and to teach, 2 until the day in which He was taken up, after having given commandment, through the Holy Spirit, to the apostles whom He chose; 3 to whom He also presented Himself alive, after He suffered, by many proofs; being seen by them during forty days, and speaking the things concerning the Kingdom of God.
4 And, being assembled together with them, He commanded them not to depart from Jerusalem, but to wait for the promise of the Father, which said He, "Ye heard from Me; 5 because John, indeed, immersed in water, but ye shall be immersed in the Holy Spirit, not many days hence."