The answer of those men themselves was plain. Their despair, they said, gave way to triumphant joy because the Lord Jesus had risen from the dead, and because they were convinced of his resurrection by the empty tomb and by the appearances of Jesus himself. No other real explanation has yet been discovered to account for the sudden transformation of the despair of the disciples into triumphant joy. The very existence of the Christian Church itself, therefore, is the strongest testimony to the resurrection; for without the resurrection the Church could never have come into being. Acts 1:12-26 After the ascension of Jesus, which was studied in the last lesson, the apostles returned to Jerusalem, and obeyed the command of Jesus by waiting for the coming of the Holy Spirit. But the period of waiting was not a period of idleness; it was spent, on the contrary, in praising God and in prayer. One definite action was taken--the place of Judas, the traitor, who had killed himself in his remorse, was filled by the choice of Matthias. Acts 1:15-26. At that time, certain women and a number of other disciples were gathered together with the apostles, making a total of about one hundred and twenty persons. It was upon that little company of praying disciples, or rather upon the promise of Jesus which had been made to them, that the hope of the world was based. Acts, Chapter 2 At last, at the feast of Pentecost, fifty days after the passover, the promise of Jesus was fulfilled; the Holy Spirit came upon the disciples to fit them for the evangelization of the world. Acts 2:1-13. They were all together in one place; there was a sound as of a rushing, mighty wind; cloven tongues, like tongues of fire, sat upon each one of them; they were all filled with the Holy Spirit, and began to speak with other languages as the Spirit gave them utterance. When the crowd came together to see the wonderful thing that had happened, Peter preached the first sermon of the Christian Church. Vs. 14-36. At the preaching of Peter three thousand persons were converted; the campaign of world conquest had begun. Vs. 37-42. The campaign from the beginning was a campaign of witnessing, in accordance with Jesus' command. Acts 1:8. The Christian Church was to conquer the world, not by exhorting men to live a certain kind of life, but by bringing them a piece of news. The Son of God, said the Christian missionaries, died on the cross and then rose again. That was the good news that conquered the world. Christianity from the beginning was a way of life, but it was a way of life founded upon a piece of news, a way of life founded upon historical facts. The meaning of the facts was not revealed all at once, but it was revealed in part from the very beginning, and throughout the Apostolic Age the revelation came in greater and greater fullness, especially through the instrumentality of Paul.