Elder Paisios when approached by a person who was seeking help for a brother who was seriously ill gave the following advice:
Tell him to go to Confession, receive Holy Communion and consciously join the Church; very soon he will feel better.The Church has a great reservoir of spiritual powers in its Sacramental life. We must remember to properly humble ourselves and participate in them regularly. One that is avoided for dangerous reasons is the sacrament of Holy confession. It is said by many to be among the most powerful of the sacraments. Also when we attend Church we should always be prepared to receive Holy Communion. It is for our healing, forgiveness of our sins, for eternal life with God.
Does this mean that the Elder is telling us not to use doctors? Of course not!
I always indicate to people who suffer from physical illnesses and want to be cured to go to Christian Doctors.You see he is not negating the use of the gifts of modern medicine or any other gifts God has give to us. He is trying to encourage us to participate with faith in the greatest power of all, the Holy Spirit.
Reference: Elder Paisios of the Holy Mountain, p 139