What was reverend john hales' main motivation

His good intentions and sincere desire to help the afflicted motivate him.

Unfortunately, Hale is also vulnerable. His zeal for discovering witchcraft allows others, particularly Abigail, to manipulate him. The amount of evidence for witchcraft when he arrives in Salem overwhelms him. Although Hale remains determined not to declare witchcraft unless he can prove it, the expectations of the people of Salem sweep him up, and, as a result, he takes their evidence at face value, rather than investigating it himself.