Elder Joseph B. Wirthlin (1917–2008) of the Quorum of the Twelve Apostles explained what it means to be pure in heart:
“To be without guile is to be pure in heart, an essential virtue of those who would be counted among true followers of Christ. …
“If we are without guile, we are honest, true, and righteous. These are all attributes of Deity and are required of the Saints. Those who are honest are fair and truthful in their speech, straightforward in their dealings, free of deceit, and above stealing, misrepresentation, or any other fraudulent action. Honesty is of God; dishonesty of the devil, who was a liar from the beginning. Righteousness means living a life that is in harmony with the laws, principles, and ordinances of the gospel” (Finding Peace in Our Lives [1995], 181–82).