The good angel begs Faustus to stop searching the dark arts for "forbidden knowledge" because God’s wrath will fall upon him otherwise.
Whenever the state of Faustus's mortal soul began envisioning, the good and the bad angel appeared. The good angel tries to convince Faustus to return to God by renouncing his sins. The good angel and the bad angel here are the literary devices called allegory i.e., they are in concrete form, from the personification of abstract concepts. Therefore, here Good angel symbolizes Faustus's Desire to repent.