The arguments of the apostles alone, though clear and convincing, would not have removed the prejudice that had withstood so much evidence. But the Holy Spirit sent the arguments home to hearts with divine power. The words of the apostles were as sharp arrows of the Almighty, convicting men of their terrible guilt in rejecting and crucifying the Lord of glory. (AA 45.1) MC VC

Under the training of Christ the disciples had been led to feel their need of the Spirit. Under the Spirit’s teaching they received the final qualification, and went forth to their lifework. No longer were they ignorant and uncultured. No longer were they a collection of independent units or discordant, conflicting elements. No longer were their hopes set on worldly greatness. They were of “one accord,” “of one heart and of one soul.” Acts 2:46; 4:32. Christ filled their thoughts; the advancement of His kingdom was their aim. In mind and character they had become like their Master, and men “took knowledge of them, that they had been with Jesus.” Acts 4:13. (AA 45.2) MC VC

Pentecost brought them the heavenly illumination. The truths they could not understand while Christ was with them were now unfolded. With a faith and assurance that they had never before known, they accepted the teachings of the Sacred Word. No longer was it a matter of faith with them that Christ was the Son of God. They knew that, although clothed with humanity, He was indeed the Messiah, and they told their experience to the world with a confidence which carried with it the conviction that God was with them. (AA 45.3) MC VC