Elder St Paisios on Battling Bad Habits…
First of all, man must realise that such a habit is harmful to him, and then he must be willing to struggle to break the habit. One must have a lot of willpower in order to be able to break a bad habit all at once. Just as the rope rubs against the edge of the well and over the years forms a small groove that holds the rope in place, every habit forms a groove in the heart, making it then difficult to get rid of. This is why we must be very careful not to develop bad habits, because it takes a lot of humility and great willpower to overcome them. Father Tychon on the Holy Mountain used to say, “My child, a good habit equals virtue; a bad habit equals passions.”
In any case, I have found that when a man, while struggling, continues to make the same mistakes and does not change, the reason is usually egoism, self-love and self-interest. Humility and love are missing, thus blocking divine intervention. The person himself does not allow God to help him. If, for example, God helps him overcome a particular passion, such a person will selfishly take credit for it and assume that it was his own achievement, without any help from God.
– ‘Spiritual Struggle’