Socrates' 'human wisdom'

Socrates claims that he is wiser than the other citizens of Athens, even though he is ignorant. Why does he claim this? How does his 'human wisdom' relate to his God-given mission? Socrates also claims that what he is doing is highly beneficial to the citizens of Athens. Why does he believe this ? Evaluate either his claim that he is wiser than the other citizens of Athens or that he greatly benefits the citizens of Athens by questioning them as he does.