Sickness increases with impatience.
St. Tikhon of Zadonsk
Is it permissible to go to doctors for healing, and to take medications? There is no sin whatsoever in this, for everything is from our Lord God -- both the healing substances and the healers themselves. The sin is not in a man’s resorting to medical procedures, but in a sick man’s resting all of his hopes for recovery on the doctor and on medical resources, thus forgetting that everything depends upon the All-merciful and All-powerful God, Who Alone determines who lives or dies.
St. Ambrose of Optino
Inasmuch as God is life, and diseases and illnesses are deviations from life, mere contact with the source, with Original Life, heals them
St. John of Kronstadt