Jude introduces himself as a servent of Jesus Christ and the brother of James.
He proclaims mercy, peace and love upon the saints. He instructs them to earnestly contend for the faith.
Jude warns against men who deny the Lord Jesus Christ.
Jude reminds the saints that the Lord delivered the childern of Israel out of Egypt but then destroyed the unbelievers.
Jude refers to angels who kept not their first estate, which was in premortality. These angels are "reserved in everlasting chains under darkness unto the judgment of the great day."
Sodom and Gomorrha suffered the "vengeance of eternal fire."
Michael the archangel contended with the devil about the body of Moses. This story, however, is not found elsewhere in scripture.
Note that Michael is another name for Adam. Reference: Letter from Joseph Smith to The Church of Jesus Christ of Latter-day Saints, Nauvoo, Illinois, September 6, 1842. History of the Church 5:148-53.
Jude warns that corrupt men who follow the way of Cain or Balaam will face judgment and be cast into a "blackness of darkness for ever."
Cain slew his brother Able because he knew that Able did was righteous. Balaam was a man who accepted money to curse and destroy his own people. See Numbers 22-24.
Enoch prophesied that the "Lord cometh with ten thousands of his saints to execute judgment" upon the ungodly who walk after their own lusts. These mockers would be prominent in the last days.
 But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,
 Keep yourselves in the love of God, looking for the mercy of our Lord Jesus Christ unto eternal life.
 And of some have compassion, making a difference:
 And others save with fear, pulling them out of the fire; hating even the garment spotted by the flesh.
 Now unto him that is able to keep you from falling, and to present you faultless before the presence of his glory with exceeding joy,
 To the only wise God our Saviour, be glory and majesty, dominion and power, both now and ever. Amen.