Why did Saul try to go on to Damascus?
Saul went on to Damascus because there were Jewish believers up there. He was persecuting them, thinking he was doing God a service by getting them off the scene because he considered them imposters and blasphemers. Indeed, he was consenting to Stephen's death and continued the persecution.
Les explains that Saul was consenting to Stephen's death, and a great persecution arose against the assembly at Jerusalem. The Jewish believers were scattered throughout Judea and Samaria, except the apostles. Saul, however, tried to go on up to Damascus because there were Jewish believers there too. He thought he was doing God a service by getting them off the scene, since he considered them imposters and blasphemers. Les notes that the believers remained in Jerusalem despite intense persecution, yet Saul sought to pursue them even to Damascus.