Yet, I am poor and needy; come quickly to me, O God.  You are my help and my deliverer, O Lord, do not delay.

This seems to say, “though I am small and of not much importance, there is no one else who is my savior”.  it is a desperate plea of a desperate man for the Great Helper to come quickly to his aid.  I think a mere man cannot call on the only true God of the universe in this way, unless he knows Him personally and intimately.  Because of Jesus, we have this privilege.