When someone who is not Orthodox comes to the Orthodox Church he must go through a furnace of repentance, of change and regeneration of his entire way of thinking and living. This will take a long time. In order for someone’s positive attitude towards Orthodoxy to become an experience of his heart, he must lead a life of asceticism and crucifixion for many years under the guidance of an experienced spiritual father. Otherwise the ‘old self’ will remain, with the result that unbelief and the inclination to go back to the old way of life will often occur. St. Sophrony of Essex