The hard-hearted cannot feel the things of the Spirit because the barrier of personal pride does not allow the Spirit in. The scriptures often teach of the phenomenon of the heart being softened, but for most, it takes the exercise of considerable humility before one's heart can even be softened. When the scripture says the Lord changed their hearts, this implies the greatest of all spiritual transformations. All desires that were evil are replaced for righteous ones. All hatred is replaced by charity, and all things carnal are discarded for their spiritual counterpart. They have no more disposition to do evil, but to do good continually (Mosiah 5:2). This mighty transformation can come about only when the individual exercises faith in the redeeming power of Christ, your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters (Mosiah 5:7, italics added).
Ezra Taft Benson
"Can human hearts be changed? Why of course! It happens every day in the great missionary work of the Church. It is one of the most widespread of Christ's modern miracles. If it hasn't happened to you - it should.
"The Lord works from the inside out. The world works from the outside in. The world would take people out of the slums. Christ takes the slums out of the people, and then they take themselves out of the slums. The world would mold men by changing their environment. Christ changes men, who then change their environment. The world would shape human behavior, but Christ can change human nature." (The Teachings of Ezra Taft Benson, pp. 77-78.)
Howard W. Hunter
"This is the purpose of teaching. This is the reason we labor so hard, seek the Spirit, and prepare our minds with good things as the Lord has commanded, that we might be an instrument in the hands of the Lord in changing the heart of an individual. Our aim is to plant in the hearts of the children the desire to be good, the desire to be righteous, the desire to keep the commandments of the Lord, the desire to walk in humility before him. If we can be an instrument in the hands of the Lord in bringing to pass this mighty change in the hearts of the youth of Zion, then we have accomplished the great miracle of a teacher. And truly it is a miracle. We do not understand how the Lord changes the hearts of men, but he does. Through a teacher, he can change the hearts of children almost overnight." (The Teachings of Howard W. Hunter, p. 204)
Ezra Taft Benson
"This is what is meant by partaking of the 'power of God.' You teachers-you who are to teach the power of this gospel-I would ask you, 'have [you] spiritually been born of God? Have [you] received his image in your countenances? Have [you] experienced this mighty change in your hearts?' (Alma 5: 14.)
"A measure of this change of heart is what happens to the motives and desires of the gospel teacher. Enos testified that he 'began to feel a desire for the welfare of my brethren.' (Enos 9.) Alma, who also experienced this mighty change, said: 'I have labored without ceasing, that I might bring souls unto repentance; that I might bring them to taste of the exceeding joy of which I did taste' (Alma 36:24).
"May your motives be likewise as pure. May the welfare of your students be the primary motive to your teaching. May you be converted so you can strengthen your students." (Pamphlet: "The Gospel Teacher and His Message", p. 4)