Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Do not neglect the practice of the virtues; if you do, your spiritual knowledge will decrease, and when famine occurs you will go down into Egypt (Genesis 41:57, 46:6).
The mission of the Church is to bring about in her members the conviction that the proper state of human personhood is composed of immortality and eternity and not of the realm of time and mortality... and the conviction that man is a wayfarer who is wending his way in the sway of time and mortality towards immortality and all eternity.
In Christianity truth is not a philosophical concept nor is it a theory, a teaching, or a system, but rather, it is the living theanthropic hypostasis - the historical Jesus Christ (John 14:6). Before Christ men could only conjecture about the Truth since they did not possess it. With Christ as the incarnate divine Logos the eternally complete divine Truth enters into the world. For this reason the Gospel says: 'Truth came by Jesus Christ' (John 1:17).
