It is actually total humility.
Some one who says, I am the servant of God infers two – God and himself – whereas someone who says,
I am God, negates himself. He relinquishes his own existence. I am God means I don‘t exist. Everything is God. Only God exists. I am nothing. I am utter emptiness.
This is complete humility not arrogance, but people often misunderstand.
When someone says he is God‘s servant, he still sees himself as a doer, albeit in God‘s service.
He is not yet drowned in the Ocean of God.