In the first book, O Theophilus, I have dealt with all that Jesus began to do and teach, until the day when He was taken up, after He had given commandment through the Holy Spirit to the apostles whom He had chosen. To them He presented himself alive after His Passion by many proofs, appearing to them during forty days, and speaking of the kingdom of God.
-- Saint Luke the Evangelist from Acts of the Apostles 1: 1 - 3
