Speaker/Cullen
The speaker expresses his faith in God, but does not understand why God chooses to allow suffering when He is supposed to be good. Among the seemingly contradictory things God allows, the speaker says that the most "curious" one is God's choice to create black poets.
God
God is described as benevolent in the poem. However, the example of the blind mole, the existence of death, the fates of Tantalus and Sisyphus, and the difficult life of black poets appear to contradict this fundamental kindness. God is described as having an "awful brain" and "awful hand" whose actions exceed the understanding of mere mortals.
Tantalus
Tantalus is a figure from Greek mythology whose punishment for disrespecting the gods was to be condemned to remain forever hungry and thirsty with fruit and water just out of reach.
Sisyphus
Sisyphus is also a figure from Greek mythology who was punished by the gods. His fate was to eternally roll a heavy boulder up a cliff only to have it roll back down again. His name has become synonymous with neverending, futile tasks.