The blind man believed Jesus could, would, and was able to heal him.
The Blind Man had faith in Jesus, and because HE believed in Jesus, the blind man was healed.
John 3:16 - For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
John 6:47 - Verily, verily, I say unto you, He that believeth on me hath everlasting life.
Acts 16:31 - And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.
We are the believers, it is us who need to have faith in Him.