Jude doesn't mention repentance at all. The mercy of Jesus is mentioned but where is the assurance of salvation?
Jude is speaking to True Christians ----that is they are saved ------the first sentence in the passage tells you that -----what has happened is that some People who just call themselves Christians have infiltrated the true Church and are spreading False Doctrine ------
Which is so prevalent today in this world ----and Jesus in Revelation 2-3 describes this also in some of the Churches ---
New Born Christians who are called Babes in Christ can be let astray by False Preachers as they are not mature in there faith and can become confused and doubt creeps in ------and they begin to go down a wrong path -----so the term snatch out of the fire is saying ---turn the person away from the destruction and get them back on the right path -----
paradox3 ---if you and a close friend whent to view a volcano sight and your friend wandered way to close to the spewing lava where the fire burns ---I am sure you would go and tell your friend they are in danger and steer your friend to a safe distance -----
Juse describes what the ungodly are like in verses 11-12 and 13---
Verses 14-16 is a prophecy in the end times -----Jesus 2nd coming ----with all the Saints (Those who were raptured before the tribulation began )--and angels to separate the sheep --the ones who received Jesus during the 7 year ulation ----from the goats who refused to receive Jesus during the 7 year tribulation -----
New King James Version-
Now Enoch, the seventh from Adam, prophesied about these men also, saying, “Behold, the
Lord comes with ten thousands of His saints,
Enoch prophesied about this ----2nd Coming
Zechariah Prophesied about this --verse 5 below ------2nd Coming -----which is why the Old Testament is incomplete without the New Testament ---the Old Testament is the forerunner for the New Testament -----Jesus still has Prophecies to fulfill from the Old and New Testament
And 1 Thessalonians 3:13 --also gives a prophecy of the 2nd Coming of Jesus
Zechariah 14 AMP B
God Will Battle Jerusalem’s Foes
14 Behold, a day is coming for the Lord when the spoil taken from you (Jerusalem) will be divided in your midst. 2 For I will gather all nations against Jerusalem to battle, and the city will be captured and the houses plundered and the women ravished; and half of the city will be exiled, but the rest of the people will not be cut off from the city. 3 Then the Lord will go forth and fight against those nations, as when He fights on a day of battle.
4 In that day His feet shall stand on the Mount of Olives, which lies before Jerusalem on the east; and the Mount of Olives will be split in half from the east to the west by a very large valley, and half of the mountain will move toward the north and half of it toward the south.
5 You will flee by the valley of My mountains, for the valley of the mountains will reach to Azel; and you will flee just as you fled from the earthquake in the days of Uzziah king of Judah.
Then the Lord my [a]God will come, and all the holy ones (believers, angels) with Him.
1 Thessalonians 3:11-13 Amp B
11 Now may our God and Father Himself, and Jesus our Lord guide our steps to you [by removing the obstacles that stand in our way].
12 And may the Lord cause you to increase and excel
and overflow in love for one another, and for all people, just as we also do for you;
13 so that He may strengthen
and establish your hearts without blame in holiness in the sight of our God and Father
at the coming of our Lord Jesus with all His [a]saints (God’s people).
I say -----So the book of Jude does have ties to Revelation and Prophecy 
