Why Should We Keep Our Thoughts Clear?

From my experience some healings come instantly or during short period of time as others require patience, persistence and firmness of our faith. Even though faith in God or Good helps to overcome our worldly trials but often because of lack of the divine knowledge we are not able to see the end of our sufferings. When human will is added to that faith we, pressing strongly our teeth, think that we stand firmly on the ground and fulfill God