"The course of life is … run but in one way, and only once" (Cicero, On Old Age).

We live in the present but, since time does not stand still, we constantly move toward the future. We could put Cicero's teaching into modern vernacular: Our journey through life is on a one-way street and mortality, literally, is a once-in-a-lifetime experience.

At times, we might yearn to go back but there is no road leading to yesterday.

Memories serve much as souvenir post cards: reminders of where we have been or what we have done, events big and small and, most important, people who have been a part of our lives. We may reflect upon the positive, uplifting and inspiring aspects of the past. But fact remains: We can review life but we cannot relive it.

As fallible, imperfect humans, most likely we have things we would like to change if we could. However, it does little — if any — good to berate or punish ourselves over mistakes, poor decisions, transgressions or failures.

We may pay penalties, amend mistakes, repent of transgressions and correct errors. Then we move forward. We can learn from the past, but should not brood over it.

President Thomas S. Monson has given wise counsel: "The past is behind; learn from it. The future is ahead; prepare for it. The present is here; live in it" (Southern Utah University commencement, Church News, May 9, 2009).

In His loving mercy, our Heavenly Father has provided us His great plan of happiness, the core of which is the atoning sacrifice of His only Begotten Son, our Lord and Savior Jesus Christ. Through the Savior's atonement we have the privilege of experiencing a repentance process, which involves more than just feeling regret, sorrow or shame.

The Savior's atonement makes it possible for us to have a fresh start, to live joyously in the present while looking forward to the future and laying the past behind us.

In an address during the October 2000 general conference, Elder Richard G. Scott of the Quorum of the Twelve said, "There is an essential aspect of the plan of happiness of our Father in Heaven that is often ignored even though it invariably yields peace and joy. The Savior gave His life that it might be used to bless every child of Father in Heaven. This subject is widely misunderstood and often feared. Some feel that it is to be employed only by those in serious transgression, while the Lord intended that it be consistently used by every one of His children. He has repeatedly commanded His prophets and leaders to proclaim it and to speak of little else. I refer to the blessing of true, sincere, continuing repentance, the path to peace and joy. It is a conduit to the reforming power of the Lord and, when understood and used, a dear and precious friend."

The repentance process includes recognizing our sins and feeling remorse, or godly sorrow. Confessing to our Heavenly Father and, if the transgression warrants, to our authorized priesthood leader, allows us to shed feelings of remorse and sorrow. Asking for forgiveness, doing all we can to make restitution, turning away from the transgression and living the commandments are further steps in the repentance process.

The atonement of Jesus Christ, when all is said and done, is about our happiness. Lehi declared this profound truth:

"All things have been done in the wisdom of him who knoweth all things.

"Adam fell that men might be; and men are, that they might have joy" (2 Nephi 2:24–25).

The Prophet Joseph Smith said, "Happiness is the object and design of our existence; and will be the end thereof, if we pursue the path that leads to it" (History of the Church, 5:134).

That path is before us, not behind us. We cannot find the happiness Our Heavenly Father desires us to have if our gaze is a backward glance upon the past.

Because of the atoning sacrifice of Jesus Christ, our lives can be put in order — past, present and future.