It is the Holy Spirit who is causing you to persevere. In those times when you are lazy and have no enthusiasm for any Spiritual Discipline, or when you haven’t practiced a particular Discipline as you habitually do, it is the Holy Spirit who prompts you to pick it up in spite of your feelings. Left to yourself you would have forsaken these means of sustaining grace long ago, but the Holy Spirit preserves you by granting to you the grace to persevere in them.