[Joseph Fielding Smith]
When the plan of salvation was presented to the spirits of men, or intelligences spoken of by the Lord to Abraham, Lucifer, a spirit in authority, refused to accept the plan and projected one of his own into the discussion. When his plan was rejected he rebelled and drew away with him one third of the spirits, and these became fallen angels, or the devil and his servants, who are also spoken of as devils. ... These evil spirits became sons of Perdition. Cain, because of his rebellion against the light, became Perdition. All who receive the Gospel and enjoy the blessings of the Holy Ghost and to that extent that they 'know' the power of God, and then with the understanding that they are taking a course in opposition to Jesus Christ, and figuratively crucify him again so far as they are concerned, are left without forgiveness and they too become sons of Perdition. ... The Lord plainly told Cain that Satan, the devil who was cast out of heaven, desired to have him, yet if Cain would do well he should be acceptable before the Lord. Cain loved darkness and rather than hearken to the voice of the Lord he chose to do the will of Satan knowing fully that by doing so he should have dominion over Satan and become the father of his lies. What Cain did he did with his full understanding and hence he became Perdition. This power seemed to please Cain and therefore he hearkened not to the Lord and refused to keep his commandments.
[Joseph Fielding Smith, Letter to Everett Woodie, as quoted in Minutes of the Apostles of The Church of Jesus Christ of Latter-day Saints, 1835-1951, Electronic Edition, 2015]