In speaking of the ultimately unhappy state of those who have hardened their hearts, Alma warned that they would be condemned in the final judgment by their own words, works and thoughts (see Alma 12:14). That is a most unsettling idea for anyone who has contemplated the ease with which a stray thought — of any sort — can creep unbidden into one's consciousness, triggered by any of countless stimuli. Surely, we reason, a merciful Deity would not condemn us for thoughts that enter our minds without our volition. Yet the passage clearly states "our thoughts will condemn us."

But there is comfort — and a sense of empowerment — in the realization that we can, to a large extent, control the thoughts that occupy center stage in our minds.

Jesus taught, "For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: These are the things that defile a man" (Matthew 15:19-20). This passage is instructive, not just for the overt message that one's behavior and very being is a product of his thinking, but also for the more subtle idea that one indeed can choose the thoughts he thinks. The heart, after all, has long been regarded in a poetic sense as the seat of human will and desire. Ultimately, we dwell only upon those thoughts we allow to remain and desire to entertain. Not only our acts, and words, but our thoughts as well, are a function of human will.

If it is true that thoughts result from external stimuli, we can choose to surround ourselves with an environment filled with wholesome elements, be they reading material, sights, sounds or conversation. Servants of God have repeatedly admonished us to do just that.

Two and a half months ago, President Gordon B. Hinckley challenged us to read or reread the Book of Mormon, suggesting that we could do so before the end of the year. "Without reservation," he said, "I promise you that if you will observe this simple program, regardless of how many times you previously may have read the Book of Mormon, there will come into your lives and into your homes an added measure of the Spirit of the Lord, a strengthened resolution to walk in obedience to His commandments, and a stronger testimony of the living reality of the Son of God" (Ensign, August 2005, p. 6).

From the moment God's present-day spokesman on earth uttered this challenge with its accompanying promises, every reasonably literate member of the Church was faced with a choice: Heed prophetic counsel or ignore it. Accomplishing it is relatively uncomplicated, though most of us find it takes persistent, daily effort. The instruction is strikingly plain and simple — like looking at a brazen serpent on a staff (see Numbers 21:8) or washing in the River Jordan seven times (see 2 Kings 5:10-11). Is it so simple, in fact, that some will risk perishing because they ignore it (see 1 Nephi 17:41)?

Given the extent to which the thoughts we entertain add to or detract from a testimony of the truth, should we be surprised if, having ignored President Hinckley's challenge, we find the Korihors in our lives can more easily "interrupt (our) rejoicings" (see Alma 30:22)?

A flagging testimony can be rejuvenated by summoning to mind the recollection of previous spiritual experiences with which one has been blessed. Hence, Oliver Cowdery was counseled in a revelation given through the Prophet Joseph Smith: "Verily, verily, I say unto you, if you desire a further witness, cast your mind upon the night that you cried unto me in your heart, that you might know concerning the truth of these things. Did I not speak peace to your mind concerning the matter? What greater witness can you have than from God?" (Doctrine and Covenants 6:22-23).

Ultimately, of course, a testimony is a gift from God, bestowed according to His divine will. But it does not come without effort on our part, including channeling of thoughts, coupled with fervent prayer. In his resounding testimony to the people of Zarahemla, Alma declared, "I have fasted many days that I might know these things of myself. And now I do know of myself that they are true; for the Lord God hath made them manifest unto me by his Holy Spirit; and this is the spirit of revelation which is in me. And moreover, I say unto you that it has thus been revealed unto me that the words which have been spoken by our fathers are true, even so according to the spirit of prophecy which is in me, which is also by the manifestation of the Spirit of God" (Alma 5:46).

For the Spirit to manifest to us that the words of God are true, we must first fill our minds with them. And that is a choice, an act of conscious will. Truly, we do choose the thoughts that ultimately influence us. Small wonder that we are accountable for them.