"When He had said this, He spat on the ground, and made clay of the spittle, and applied the clay to his eyes, and said to him, “Go, wash in the pool of Siloam” (which is translated, Sent). So he went away and washed, and came back seeing."
Jesus healed many people while He walked the earth, but not always in the same way. In this particular miracle, the Lord used saliva, dirt and water to bring sight to the blind man. There was no power in these material things, the healing power came from the will of Jesus Himself. When He works in the lives of people, the Lord doesn't follow a formula. There are as many different ways He accomplishes His purpose, as there are individuals. However, His will and our faith are always involved. It was the Lord's will to heal the blind man, but it wouldn't have happened without the expectant faith he had to go and wash in the pool of Siloam.