9 And now Alma began to expound these things unto him, saying: It is given unto many to know the mysteries of God; nevertheless they are laid under a strict command that they shall not impart only according to the portion of his word which he doth grant unto the children of men, according to the heed and diligence which they give unto him.Part of "giving heed" to the word is having a teachable heart. The Book of Mormon teaches us very clearly that a hard heart can prevent us from understanding the word of God and that a thankful and open heart can lead us to a better understanding of God's word.
10 And therefore, he that will harden his heart, the same receiveth the lesser portion of the word; and he that will not harden his heart, to him is given the greater portion of the word, until it is given unto him to know the mysteries of God until he know them in full.
3 For he truly spake many great things unto them, which were hard to be understood, save a man should inquire of the Lord; and they being hard in their hearts, therefore they did not look unto the Lord as they ought. (1 Nephi 15)
14 And his brethren were wroth with him because they understood not the dealings of the Lord; they were also wroth with him upon the waters because they hardened their hearts against the Lord. (Mosiah 10)
32 ...I say unto you, Nay, they did not all understand the law; and this because of the hardness of their hearts; for they understood not that there could not any man be saved except it were through the redemption of God. (Mosiah 13)
3 And now because of their unbelief they could not understand the word of God; and their hearts were hardened. (Mosiah 26)
20 But few understood the meaning of those things, and this because of the hardness of their hearts. (Alma 33)
11 And Moroni was a strong and a mighty man; he was a man of a perfect understanding; yea, a man that did not delight in bloodshed; a man whose soul did joy in the liberty and the freedom of his country, and his brethren from bondage and slavery; 12 Yea, a man whose heart did swell with thanksgiving to his God, for the many privileges and blessings which he bestowed upon his people; a man who did labor exceedingly for the welfare and safety of his people. (Alma 48)
33 And the multitude did hear and do bear record; and their hearts were open and they did understand in their hearts the words which he prayed. (3 Nephi 19)
All of this leads us to a passage in 3 Nephi 11 which takes on more meaning in this context:
3 And it came to pass that while they were thus conversing one with another, they heard a voice as if it came out of heaven; and they cast their eyes round about, for they understood not the voice which they heard; and it was not a harsh voice, neither was it a loud voice; nevertheless, and notwithstanding it being a small voice it did pierce them that did hear to the center, insomuch that there was no part of their frame that it did not cause to quake; yea, it did pierce them to the very soul, and did cause their hearts to burn.
4 And it came to pass that again they heard the voice, and they understood it not.
5 And again the third time they did hear the voice, and did open their ears to hear it; and their eyes were towards the sound thereof; and they did look steadfastly towards heaven, from whence the sound came.
6 And behold, the third time they did understand the voice which they heard; and it said unto them:
7 Behold my Beloved Son, in whom I am well pleased, in whom I have glorified my name—hear ye him.
8 And it came to pass, as they understood they cast their eyes up again towards heaven; and behold, they saw a Man descending out of heaven;
These were good people who had survived tremendous darkness and destruction and had gathered at the temple. They knew they had witnessed the signs of Christ's coming, and yet they still didn't understand the voice (despite its penetrating power) until the third time they heard it, after they had opened their ears, pointed their eyes to heaven to look "steadfastly" whence the sounds came. Only then did they see the Savior.
Perhaps there are metaphorical lessons for us to learn from this. It is not enough to feel the Spirit. We must take certain steps in order to be truly prepared to experience the power of Jesus Christ in our lives.