This is a principal I learned under god's tender tutoring hand. It is a true principal and if followed will help you make many good decision's in life.
Once you have made a commitment to be true to god the Adversary will step in and tempt you to abandon your dedication. He will tempt you to think it's okay to let down your guard just this once and then you will make the decision to change. Of course, this is false. But how can you know if this is temptation from the opposition? How can you decide to decide to live the Commandments of God? A dedicated person who wants to be true to his covenants may fall in his efforts to be true, but the fall should never keep him down. He can get up, regroup and decide again and again until he gains the strength to remain true. It isn't easy, But it is possible to make this decision.
"Our destiny and ultimate fate depend on our daily decisions. Tomorrow's joy or despair has it's roots in decisions we make today. Those who stand at the threshold of life always waiting for the right time to change are like the man who stands at the bank of a river waiting for the water to pass, so he can cross on dry land." Joseph Smith made the right choice of praying to god at the right time for an answer to his questions. We are his children whom he loves and we have that same right. But, We must decide to decide.- Joseph B. Wirthlin "The Three Choices" Ensign- Nov. 2003