"The faster you acquire a virtue, the easier it is lost. The more slowly and laboriously you acquire it, the more steadfastly it remains; just like that squash plant that grew tall and said to the cypress tree, "See how much I've grown in just a few days! You've been here for so many years and haven't grown much at all!" "Yes," said the cypress tree, "but you still haven't seen storms, heat waves, and cold spells!" And after a little while, the squash plant dried up, while the cypress tree remained where it was.
"This is also how a spiritual man is. Both during a storm and during times of peace he remains the same. Why? Because the long period of time has created stability. When he first renounced the world, his spiritual condition was unstable, but with time, the grace of God gradually worked out his salvation and freedom from the passions. Thus, a person needs to force himself today, and the grace of God will start acting by itself tomorrow. Then you will not need to force yourselves to have good thoughts; the grace that remains within you is what brings them to your mind without your effort. Then you will see great mysteries! You will have a feeling, so to speak, of the remembrance of death, or of another beneficial recollection.
When you wake up and are still opening your eyes, instead of feeling sleepy, you will have progressed; you will have already passed through the entire mystery of theoria and will say, "But how does this thing happen, since I am still getting up? How does this thing happen?" All the same, the grace of God acts by itself---it is the result of a long-standing habit.
"The same thing happens with sin: whether awake or sleeping, a sinful man constantly thinks about evil. When sin is helped by a bad habit and by the devil, it becomes a constant evil. Likewise with good; a good habit assisted by the grace of God becomes second nature to him."
Elder Ephraim Arizona