When Avraham arrived, the world was steeped in idolatry. The first mention of a bris (covenant) is the rainbow after the flood. When Rabbi Shimon Bar Yochai was alive, no rainbow was seen in the sky. The rainbow represents confusion and the confrontation between good and evil. Avraham's uniqueness is that he worked very hard to see and believe in Hashem. Non-Jews need to see to believe, but we listen first. Despair leads to hedonism. A person of true emunah (faith) is strengthened by seeing and experiencing suffering.