One of the challenges in the heart book is to read all the scriptures in the topical guide under "heart." I'm almost done and it has been a very interesting/enlightening experience. I've learned a few things (or solidified a few things).
First, the term "pure in heart" doesn't just pertain to morality/virtue. In fact, and this is probably because of my age, but what stood out to me most is that pure in heart means lots of things including motivation/desire.
For example, Proverbs 17:22, "For as he thinketh in his heart, so is he . . ." or Hebrews 4:12 which says that God is a ". . . discerner of the thought and intents of the heart" with "intents" here linked to "motivations" by a footnote. How about James 4:8, " . . . purify your hearts, ye double-minded." It is saying that hypocrisy or the desire to do something other than what we are doing rests in our hearts. God can see our intentions as clearly as our actions. I'm pretty sure those with pure intentions, those with a strong desire to do right, receive grace and get counted among the pure in heart despite mistakes.
Pure in heart can also be connected to turning to the Lord (softening your heart), turning away from the Lord (hardening your heart or losing your desire to obey and believe), embracing the commandments, feeling the joy of the Atonement, being taught by the Spirit, and communing with God. I didn't realize that in the scriptures our spirituality or spiritual health is all talked about through the word "heart." Obviously, the scriptural heart is the center of all things spiritual while the physical heart can, arguably, be the center of our physical health. More symbolism?
These scriptures are amazing in their range. 1 Samuel 7:3, ". . . prepare your hearts unto the Lord." In other words, if you want to be taught by the Spirit, you have to purify your life.
1 Samuel 16:7, ". . . for the Lord seeth not as man seeth; for man looketh on the outward appearane, but the Lord looketh on the heart." The Lord cares about our spiritual health.
Ezra 7:10, "For Ezra had prepared his heart to seek the law of the Lord, and to do it . . .." Clearly, Ezra's motivations/desires were pure and he wanted to follow belief with action. (Did everyone else know there was a biblical Ezra and I'm just not much of a scriptorian?)
Proverbs 17:22, "A merry heart doeth good like a medicine." Our joy in the Savior is rooted in our "heart."
Proverbs 17:3, "The fining pot is for silver, and the furnace for gold: but, the Lord trieth the hearts." To the Lord everything is spiritual, but we forget that sometimes. All trials are a test of our desires/beliefs/faith/willingness to obey, and all those other things that are rooted in our hearts.
Isaiah 51:7, "Hearken unto me, ye that know righteousness, the people in whose heart is my law . . .." This one seems important. If our spiritual center is our heart, then the commandments had better be emblazoned there, with the requisite desire to follow through. If only a few commandments are imprinted on our hearts or if the commandments are only resting there, then it will be easy for our hearts to harden.
Ezekial 11:19-20 says something like, "God will take out my stony heart and give me a heart of flesh." Or, God will help me want to believe and then to believe.
Matt 6:21, "For where your treasure is, there will your heart be also."
Matt 11: 28-30, "Come unto me and I will give you rest/all ye that labor/for I am meek and lowly in heart and ye shall find rest (that was a paraphrase)." Jesus is meek and lowly in heart because his desires/motivations are perfectly aligned with Heavenly Father. He isn't kicking against this commandment or this one or why isn't my life going the way I planned. Also, His motives are completely pure--He just wants to help us. When we go to him we find rest because there is nothing of competition or angling. He loves us purely and unselfishly.
Luke 24:32 says that we feel the Holy Ghost in our "hearts." If we want revelation, if we want confirmation, we have to fix our hearts. Romans 10:10, "For with the heart man believeth unto righteousness . . .."
John 12:40, "Let not your heart be troubled." If we've given our hearts to the Savior, we need to let a lot of worry go. If we're asking for and receiving revelation, our lives will go where they should. We might feel sorrow, but we shouldn't feel fear.
Acts 2:37, "pricked in their hearts." Our conscience also lives in our "hearts."
Acts 4: 32, "And the multitude of them that believed were of one heart . . .." " . . . because the love of God is shed abroad in our hearts by the Holy Ghost which is given unto us." Romans 5:5. Ephesians 3:16-21, ". . . that ye, being rooted and grounded in love, may be able to comprehend . . . and to know the love of Christ." When we are pure in heart we want to take care of others and our ability to feel love and give love increases.
I have no summary remark. I haven't finished reading all the scriptures yet, but seeing my "heart" as my spiritual center helps me visualize whether or not it is healthy and open, or shut down. Good stuff.