But is prayer the cause of such deception? May it not be. And if for this you find fault with mental prayer, then you should also consider the knife to be at fault if a small child, because of his senselessness at play, should happen to stab himself with it. Likewise, in your view, one should also forbid soldiers to use the military sword which they receive to fight the enemy, if some senseless soldier should happen to stab himself with his own sword. But just as the knife and the sword are not guilty of any fault but only accuse the senselessness of those who stab themselves with them, so likewise the spiritual sword, sacred mental prayer, is innocent of any fault, but rather the self-will and pride of the self-willed are the cause of demonic deceptions and every spiritual harm.
St. Paisius (Velichkovsky)