Saul's Expedition to Damascus  (Acts: 9: 1-2)

"As for Saul, he continued to breathe out murderous threats against the Lord's disciples. He went to the high priest and asked him for letters to the synagogues of Damascus, so that, if he found any followers of The Way there, men or women, he might bring them in chains to Jerusalem."

We see here the telling of Saul of Tarsus and his repressive campaign against believers in Jerusalem. But Saul was not content with driving out believers in the Christ only from Israel; he was determined to pursue them to wherever they had fled.

As an independent state of the Romans, Israel had the right of extradition through its high priest and the provincial administration. Thus, the high priest had authority to grant Saul the legal means to return refugees to Jerusalem from Damascus, including followers of The Way (followers of Christ). The possible charge: complicity in Stephen's offense against the temple.

Damascus was a city going back to the days of Abraham, and later it was the administrative seat of an Assyrian province. And still later it belonged to the Roman province of Syria. A very large Jewish population lived in Damascus, with several synagogues.

The Light and Voice from Heaven (Acts: 9:3-7)

"As he went on his way he was approaching Damascus when suddenly as light from heaven flashed round about him. He fell to the ground, and heard a voice saying to him, 'Saul, Saul, why are you persecuting me?' 'Who are you, my lord?' he asked. The other said, 'I am Jesus, the one you are persecuting. But get up and go into the city, and you will be told what you must do.' The men who were traveling with him [Saul] stood speechless; they heard the voice but did not see anyone."

Saul set out for Damascus, carrying the high priest's commission, and had almost reached the city at midday when suddenly there was a voice and light of divinity from heaven. The voice may have been what rabbis called "the daughter of the voice [of God]", the heavenly echo. The light was so intense that it outshone the sun.

This passage doesn't expressly say that Saul in fact saw the risen Christ and heard his voice on the Damascus road; however, their reality is confirmed in the words of Ananias (v. 17) and Barnabas (v. 27). In addition, Saul's own later references of conversion strongly imply that he both saw the risen Christ and heard his voice say "I am Jesus" on that most significant day. 

In the words of the 18th century statesman, George Lyttelton, "the conversion and apostleship of St. Paul alone, duly considered, was of itself a demonstration sufficient to prove Christianity to be a divine revelation."