Hell hath both an entrance and an exit
During this hundred years many other great truths not known before, have been declared to the people, and one of the greatest is that to hell there is an exit as well as an entrance. Hell is no place to which a vindictive judge sends prisoners to suffer and to be punished principally for his glory; but it is a place prepared for the teaching, the disciplining of those who failed to learn here upon the earth what they should have learned. True, we read of everlasting punishment, unending suffering, eternal damnation. That is a direful expression; but in his mercy the Lord has made plain what those words mean. “Eternal punishment,” he says, is God’s punishment, for he is eternal; and that condition or state or possibility will ever exist for the sinner who deserves and really needs such condemnation; but this does not mean that the individual sufferer or sinner is to be eternally and everlastingly made to endure and suffer. No man will be kept in hell longer than is necessary to bring him to a fitness for something better. When he reaches that stage the prison doors will open and there will be rejoicing among the hosts who welcome him into a better state. The Lord has not abated in the least what he has said in earlier dispensations concerning the operation of his law and his gospel, but he has made clear unto us his goodness and mercy through it all, for it is his glory and his work to bring about the immortality and eternal life of man. (Elder James E. Talmage, Conference Report, April 1930, 97)
You ask, Can a man do any wrong without first being tempted of Satan? All men have their agency, the spirit of Satan leads to error and darkness and wrong doing. If a man does wrong, it is because he yields to the spirit of evil, thereby exercising his agency. If he does good, it is in accordance with the spirit that is of God, and he uses his agency in that as well. Those who overcome evil in this life will be beyond the power of Satan in the life to come. In other words, Satan’s power ends in this world so far as the righteous are concerned, for they arise above him and above his influence; and power is not given to him to tempt them in the spirit world, they having overcome him in this. So far then as the righteous are concerned, Satan is effectually bound, whether it is in this life or in the life to come. But as mortality is never free from its own weaknesses there is no perfect safety in this sphere without the presence continually of the influence of the Holy Spirit. Satan can enter any place where he is invited or permitted to enter by man. If wicked men enter the house of God or have dominion in it, Satan will have access there, but where the righteous rule and the righteousness of God prevails, there Satan cannot come, at least with power. (Joseph F. Smith, From Prophet to Son: Advice of Joseph F. Smith to His Missionary Sons, compiled by Hyrum M. Smith III and Scott G. Kenney [Salt Lake City: Deseret Book Co., 1981], 70-71.)
That part of the spirit world inhabited by wicked spirits who are awaiting the eventual day of their resurrection is called hell. Between their death and resurrection, these souls of the wicked are cast out into outer darkness, into the gloomy depression of Sheol, into the Hades of waiting wicked spirits, into hell. There they suffer the torments of the damned; there they welter in the vengeance of eternal fire; there is found weeping and wailing and gnashing of teeth; there the fiery indignation of the wrath of God is poured out upon the wicked. (Alma 40:11-14; D. & C. 76:103-106.) (McConkie, Mormon Doctrine, p. 349.)
Until the death of Christ these two spirit abodes [paradise and hell] were separated by a great gulf, with the intermingling of their respective inhabitants strictly forbidden (Luke 16:19-31). After our Lord bridged the gulf between the two (1 Pet. 3:18-21; Moses 7:37-39), the affairs of his kingdom in the spirit world were so arranged that righteous spirits began teaching the gospel to wicked ones (Bruce R. McConkie, Mormon Doctrine, p. 762).