The beauty of the Gospel is that, when fully understood, it allows us to exercise the faith required to rend the veil that separates us from God. Everyone who lives in this world while seeking for a better one encounters the challenge that the veil of unbelief (Ether 4:15, Alma 19:6) poses. The mystery, then, is how to commune with the Lord through the veil, pierce it, and receive His presence. While there is a great veil of unbelief that keeps you from seeing and communing with the heavenly hosts, there are also smaller "veils of unbelief" that keep you trapped in bad habits, downward addictive cycles, immoral practices, and other negative patterns of behavior. All these principles apply to breaking through the lesser veils of unbelief in your life, too.
The canon of LDS scripture is a strong resource for understanding those things. We learn how we are to attain glory and intelligence in this life, to see the face of God, and to have our calling and election made sure. Uniquely Mormon scripture (the Book of Mormon, Doctrine and Covenants, and Pearl of Great Price) and teachings (sermons and teachings from Joseph Smith, covenants and temple rites, and the Lectures on Faith) make the following very clear: those great spiritual gifts and events aren't a privilege reserved only for a spiritual elite; they are something that the Lord desires all to receive. All that is needed is to: forsake your sins, come unto Christ, call on His name, and obey His voice (D&C 93:1). You don't have to be a spiritual, intellectual, or doctrinal giant to have your calling and election made sure or to see the face of the Lord, for the Lord is no respecter of persons (D&C 1:35, 38:16). Receiving one's calling and election made sure and seeing His face is one of the final spiritual milestones we receive in this life; therefore, because there is no limitations upon who can receive those things, there is no limitations on who can receive any number of spiritual gifts, depending on the diligence a person gives unto the Lord and His spirit.
Man is spirit (D&C 93:33) and was in the beginning with God (D&C 93:29), whose glory is intelligence, or the light of truth (D&C 93:36). All truth and intelligence are independent in that sphere in which God has placed them, to "act for itself... otherwise there is no existence" (D&C 93:30). We are intelligent beings; our glory, to the degree that we have any, is intelligence as well. The Lord described the spirits of men as "intelligences" to Abraham (Abraham 3:21), therefore, when the Lord states that all intelligence is independent to act for itself in the sphere in which God places it, it describes us: we are put into a sphere, designated by God, to act for ourselves, and by those actions either gain or lose intelligence. The degree to which we can act is determined by our faith, which is the principle of action in all intelligent beings (LoF 1:9).
Men are born on a level playing field. In the beginning men were innocent and become, upon birth, innocent again in Christ, who redeemed all mankind from the Fall (D&C 93:38). All men are then left to grow according to the natural intelligence they come into the world with, following their great exemplar, Christ, who "received grace for grace; and he received not the fullness at first, but continued from grace to grace, until he received a fullness" (D&C 93:12-13). Christ underwent this process perfectly, but we experience something different: we fall. When we fall from grace, and thereafter whenever we sin, "that wicked one taketh away light and truth, through disobedience, from the children of men, and because of the traditions of their fathers" (D&C 93:39). Remember that "light and truth" is intelligence, the glory of God. Therefore, the result of our own personal sins is a loss of crucial God-like intelligence, and God-like glory. We lose a critical part of us that was once ours. The story of Adam and Eve is meant to be projected into our own lives, and serves as an allegory of our own fall from grace, and the temple endowment and ceremonies designate a path to return to the Lord. By disobedience to God, we lose intelligence, but through repentance and returning to God, we gain intelligence, and can even regain all the intelligence we once lost.
One of the results of the Fall is that we are cut off from the direct presence of the Lord and His goodness. Regaining the intelligence we first lost due to our personal Fall requires us to re-learn some things about God that we knew in the beginning, but forgot (LoF 2:2-5, see also LoF 2-7). Regaining that knowledge and intelligence redeems us from the Fall and allows us to be brought back into the presence of the Lord (Ether 3:13).
In Christ's Sermon on the Mount, which he delivered almost verbatim to the Nephites as well, he gave them a commandment: "Ye are therefore commanded to be perfect, even as your father which is in heaven is perfect" (JST Matthew 5:48, see also 3 Nephi 12:48). The root of the Greek word translated as "perfect" denotes being "complete, finished, [or] fully developed" (see Matthew 5:48, footnote B, in the current edition of the LDS KJV Bible).
If we are to understand this idea of being "perfect", we would do well to understand in which way we are supposed to be perfect. There is a difference between "perfection" and "fullness". The Father is a being of "spirit, glory and power: possessing all perfection and fulness" (LoF 5:2). How are we to understand that the Father has a "fulness"? If His glory is intelligence, and he contains a fullness of that intelligence, then He contains all intelligence that exists, as is evidenced by His statement to Abraham, that "I am the Lord they God, I am more intelligent than [all other intelligences]" (Abraham 3:19). In other words, the Father possesses all intelligence and glory, and He is complete, finished, and fully developed in the sphere of existence in which He resides because of it. That makes Him more intelligent than all other intelligent beings.
How, then, are we to follow the commandment of Christ and to become perfect, even as our Heavenly Father? If the Father is "perfect" by obtaining the degree of intelligence required to be fully complete in His own sphere, then it stands to reason that we become perfect by obtaining the degree of intelligence required to be fully complete in the sphere in which God has placed us. By doing so, we, like the Earth, abide a Celestial law, because we fulfill the measure of our creation and don't transgress the law (D&C 88:25-26). D&C 93:11-19 helps us understand the measure of our own creation: we become like God by doing the things Christ did, and we worship God by growing from grace to grace and attaining more light and truth.
The difficulty that arises in that journey is that no man or earthly source can tell us what we yet lack. To obtain that information, we need to go directly to God, learn how to discern the voice of His Holy Spirit to us, and learn how to be obedient to that spirit. That is why the wise virgins of the last days are those who have "taken the Holy Spirit for their guide, and have not been deceived" (D&C 45:57). To truly follow the Gospel of Christ, you must use, as your primary guide, the Holy Spirit of God. We must make the Holy Ghost our guide, allow it to inform us of our mistakes, and follow its dictations to us. That is a lifelong quest, and cannot be completed in a day or a week, or even a year. If we fail to undertake that quest, however, we will be unable to cultivate enough faith to receive salvation, and will receive, as our eternal inheritance, a Telestial glory; those who are "liars... [and] love and make a lie...", and are "some of one [prophet], and some of another [prophet]... but receive not the gospel, neither the testimony of Jesus, neither the prophets, neither the everlasting covenant" (D&C 76:99-103). The unwise fail to "receive" the testimony of Jesus, to receive the prophets, and to receive the everlasting covenant, because they failed to receive the Holy Spirit. Without setting their primary guide as the Holy Spirit, a person cannot understand or receive the message of a true prophet, because instead of receiving the message as it's intended, they will become "of" that prophet and follow the prophet instead of following whom the prophet testifies of: Christ. Those who set up idols in their hearts and then go to a true prophet for guidance will be misled according to the idols of their hearts (see Ezekiel 14, which Joseph Smith preached from at the first conference of the Church, and recited to the Relief Society at the end of the Church, saying that it applied both to the corrupt state of the ancient Jewish church, as well as to the then-current state of the LDS Church). Therefore, finding and following a true prophet will do a person no good unless they seek to follow God through the Spirit.
If this task seems overwhelming, take heart! The Gospel plan is designed to help us navigate the tricky waters of overcoming the world, returning to God, and receiving the eternal prize. It is not requisite that a person should run faster or labor more than they have strength or means, but we do need to be diligent in doing what we have been commanded to do (D&C 10:4). We must follow the law which we have been given through our Lawgiver, Christ. And what is the law that we have been given? The Light of Christ which is in all things is the law which governs all things (D&C 88:13), and the word of the Lord is His law (132:19). Those who die without law will be judged, not according to the law they didn't have, but according to what they did have (D&C 45:54, D&C 76:71-73). Therefore, if the light of God and word of God is His law, and we are sanctified or "made holy" by obeying His law (D&C 88:34), then we are made holy by obeying the word of God to us, which is delivered by the Holy Spirit. Conversely, we are "cursed" by hearkening unto the words, philosophies, and precepts of men, unless those words are delivered by the power of the Holy Ghost (2 Nephi 28:31). The key is to learn to discern the voice of the Spirit so that you may know when it speaks to you, so that you may obey its promptings and keep the law, that you may be justified and sanctified by it. Learning how to listen to the Spirit takes time, patience, practice, trial and error, and (most of all) faith, hope, charity, and courage.
We are kept back by unbelief, which can denote either too little faith in the things that are true, or too much faith in things that are untrue. Joseph Smith stated that, regarding the full power of the Melchezidek priesthood, that "angels desire to look into [or understand; achieve] it, but they have set up too many stakes" (History of the Church, 5:554). In another account of the same sermon, Joseph is quoted as saying that "Men will set up stakes and say thus far will we go, and no farther. Did the Savior? No. [He set] up no stake[s], but [came] right up to the mark in all things" (Words of the Prophet Joseph Smith, p. 245). In the next life, angels are differentiated from "gods" because of the degree of obedience to the Gospel they exhibited here, the sacrifices they made while mortal, and the resulting blessings they obtained. Those who will be gods are more obedient and sacrificed more in this life, and therefore they received greater blessings from God in the next (see D&C 76:50-58, D&C 132:18-19, LoF 6:7-10). Notice that, in Joseph Smith's quote, he notes that is the angels themselves that set up too many "stakes". Stakes denote boundaries that are not to be crossed. God doesn't set those kinds of boundaries that kept the angels back; He places a mark that must be reached. The reason, then, that the angels do not receive the blessings that the gods receive is that angels hold themselves back by their own false beliefs of what God is like, and what He will and will not require. The common theme is that those blessings of godhood are reserved for someone else: someone smarter, or seemingly more spiritual, or in an authority position, or better looking, or taller, or whatever. Those who will be angels fail to rise up to the status of gods because they don't believe it possible. They don't have the faith that they can achieve those blessings, therefore they do not cultivate enough faith to put in the required obedience and sacrifice necessary to obtain said blessings.
These false boundaries are set in two ways: we inherit unbelief because of the traditions of our fathers, and we erect our own false boundaries because of our own lack of intelligence. Incorrect "traditions of [one's] fathers" include anything from false religious ideas (such as an inadequate knowledge about the characteristics of God) to false political ideologies; from false philosophical systems to false economic beliefs. The common factor is that they keep a person from accepting the fullness of the Gospel, and so they are held back from having the faith requisite to pierce the veil of their own unbelief. They then fail to obey the commandments of God and to sacrifice for His sake, and are kept back from being gods. False traditions kept the Lamanites from believing the Gospel (Mosiah 10:12, Helaman 15:15, Alma 9:16). Also, when we sin, we lose critical light and truth. Because of that, we forget the fullness of the Lord's promises to us, and we begin to disbelieve that it is possible for us to receive His promises. If we don't repent, we soon begin to erect our own stakes that keep us from understanding and doing the Lord's will. In fact, "priestcraft and iniquities" were the primary reasons that the Jews rejected and crucified Christ (2 Nephi 10:3-5).
Walking away from those stakes and those false beliefs requires repentance, which includes gaining more light and truth from God through receiving and doing the will of the Lord (3 Nephi 14:24-27) and not hardening our hearts against His word (Alma 12:10-11). If we do that, we will grow up to the stature of Christ, and draw ever closer to the perfect day.
Let us be doers and hearers of the Word, that we may pierce through the veil of unbelief in our own lives, and lay hold on the greatest blessings of the Gospel, which the Lord intends for us all to receive.