Saint Theophan the Recluse. Letters. Issue 4. From the letter 322.
No need to be afraid of delusion. It happens with the proud people only... who begin to think that as the warmth has entered their hearts, this is already the end of perfection. And here is just the beginning, and, perhaps, it is not durable. For both warmth and peace of heart are natural, the fruit of concentration. But you have to work tooth and nail, and wait until the natural is replaced by the grace. Anyway, the best of all is never to consider yourself to have achieved something, but always see yourself as a beggar, naked, blind and worthless.