Not every day is a great time of bible reading and prayer even when we want to. The cares of this world, work deadlines, emotional state, ability to understand, lack of bible study tools and a variety of other reasons can cause us to not persevere. These are good reasons that may cause us to be discouraged by our own inconsistency and not even make a goal to have a quiet time. However I have seen that having an inconsistent sincere time of prayer is better for my spiritual growth than none at all. As I try to be consistent, sooner or later the words of the Bible speak to my situation and provide me wisdom to handle the different tests we face in this life.