The purpose of this life is to learn to distinguish between good and evil and to choose good. Human beings are inherently rational. We do not choose evil because we love evil, we choose evil because we are blind to the true consequences of choosing evil. Satan's main tactic is to misrepresent the true consequences of sin. We are blind to the true consequences of evil because we love evil and do not search in the light. In order to search for further light and truth, one must be ready and willing to part with any and all false traditions. This means having a willingness to have what are now positive things in your life turn bitter. It is gutwrenchingly unpleasant. To those who will let him do it, God will show that there is nothing Telestial that is worth the cost. The only thing in this kingdom that is worthwhile is to keep God's commandments, because God's commandments belong to a higher state of glory than where we find ourselves at present. Many are frustrated in their attempts to overcome sin because they are trying to defeat problems of this kingdom without obtaining knowledge pertaining to a higher kingdom. They think that sin can be overcome if one feels guilty enough about it, or if one has enough negative worldly consequences (such as peer pressure), or if one prays hard enough for God to suspend their agency and magically take sin away. Those solutions will not change a person's character. The only way to overcome sin is to learn to see things as they really are--as God sees them. This requires new knowledge. New knowledge changes your perspective on all things in life. New knowledge brings you to the point where sin has no power over you--not because you have been magically changed or because God has suspended your agency, but because you are a rational being, and God has revealed to you parts of the equation that were previously unknown to you. These are mysteries of Godliness, and God cannot reveal them to the world. It would be unmerciful to do so because Telestial beings cannot bear them. Telestial beings require the illusions of this life to endure the pain of this life. If God revealed to them the truth of the things they treasure, life would be so miserable as to guarantee suicide (though even suicide is no consolation to those who see things as they really are). Only as they submit to the Spirit can they become strong enough through faith in Christ to endure the suffering of this kingdom without the counterbalance of Telestial (counterfeit) comforts and pleasures. One is saved no quicker than he can obtain knowledge because it is your degree of knowledge that determines your degree of sinlessness.
I don't have time to polish this now, but I am dumping quotes and verses here for later:
"Knowledge saves a man and in the world of spirits a man can't be exalted but by knowledge. So long as a man will not give heed to the commandments he must abide without salvation. A man is his own torment. 115 Hence the saying they shall go into the lake that burns with fire & is as exquisite as a lake & so is the torments of a man" (Joseph Smith, WOJS 7 April 1844)
"If we get puffed up by thinking that we have much knowledge, we are apt to get a contentious spirit, and knowledge is necessary to do away contention. The evil of being puffed up is not so great as the evil of contention. 3 Knowledge does away darkness, supense and doubt, for where Knowledge is there is no doubt nor suspense nor darkness. There is no pain so awful as the pain of suspense. this is the condemnation of the wicked; their doubt and anxiety and suspense causes weeping, wailing and gnashing of teeth. 4 In knowledge there is power. God has more power than all other beings, because he has greater Knowledge, and hence he knows how to subject all other beings to him." (Joseph Smith, WOJS 8 April 1843)
"At 10 Prest. J. preached on 2nd Peter Ch 1. He shewed that knowledge is power & the man who has the most knowledge has the greatest power. Also that salvation means a mans being placed beyond the powers of all his enemies. " (WOJS 17 May 1843)
"He spoke of the importance of our understanding the reasons and causes of our exposure to the vicissitudes of life, and of death; and the designs and purposes of God, in our coming into the world, our sufferings here, and our departure hence—that it is but reasonable to suppose that God would reveal something in reference to the matter—the ignorance of the world in reference to their true condition, and relation. Reading the experience of others, or the revelations given to them, can never give us a comprehensive view of our condition and true relation to God. Knowledge of these things, can only be obtained by experience in these things, through the ordinance of God set forth for that purpose. 3 He remarked that the disappointment of hopes and expectations at the resurrection, would be indescribably dreadful. That the organization of the spiritual and heavenly worlds, and of spiritual and heavenly beings, was agreeably to the most perfect order and harmony—that their limits and bounds were fixed irrevocably, and voluntarily subscribed to by themselves—subscribed to upon the earth—hence the importance of embracing and subscribing to principles of eternal truth. He assured the saints that truth in reference to these matters, can, and may be known, through the revelations of God in the way of his ordinances, and in answer to prayer. The Hebrew church "came unto the spirits of just men made perfect, and unto an innumerable company of angels, unto God the Father of all, and to Jesus Christ the Mediator of the New Covenant;" but what they learned, has not been, and could not have been written." (Account of Discourse by Joseph Smith, WOJS 9 Oct 1843)