(a) The circumstances were that when Saul, the unbeliever who persecuted the Christians, collected letters of introduction to synagogues in Damascus, to enable him arrest Christians in the city. He planned to bring the arrested Christians / believers bound to Jerusalem for persecution. As he approached Damascus, a light from heaven flashed around him. He fell to the ground and heard the quoted voice. After hearing the voice, Paul then asked, "who are you Lord" and the voice replied, I am Jesus, whom you are persecuting. Rise and enter the city and you would be told what to do. The man who were traveling with him stood speechless hearing voices, but seeing no one. He discovered he was blind and was led by hand into Damascus.
For three days, he neither ate nor drank. Meanwhile, the Lord spoke to Ananias in a vision to go to the house of Judas (in Straight Street) and ask for Saul of Tarsus. Ananias was further told that Saul had, while praying, seen him in a vision laying hands on him so that he might regain his sight. But Ananias protested and explained that he had heard a great deal about Saul's persecution of Christians in Jerusalem, and that he had actually come to Damascus with the aim of binding believers. The Lord insisted that Ananias should go to Saul whom the Lord said He had chosen as an instrument for the proclamation of the Gospel. The Lord promised to show Saul, how much suffering he would undergo for the Lord's sake. Ananias therefore went to Saul and informed him that the Lord who appeared to him on the way to Damascus, had sent him to him, that he might regain his sight. Immediately, something like scales fell from his eyes and he regained his sight. Then Saul arose and was baptized.

(b) Ways in which this experience affected Saul's life are:
(i) Saul was transformed from being a persecutor of the Christians to a defender of Christianity.
(ii) It also changed him from its former devotion to the Law, to a complete devotion to Jesus Christ.
(iii) Paul became an apostle to the Gentiles and from there, the early church enjoyed peace. As the Lord predicted, Saul endured untold persecution in his efforts to propagate the gospel.