Personally, I think there is good reason to accept “Jesus” in Jude 5 as the intended and original word. Although, I’m not against the others, I do think they miss the greater context of the letter’s overall communication
First, in Jude 3, he speaks of our common salvation, the shared deliverance, which is not a commodity, but Jesus Himself. For instance in 1Co 1:30, Paul says Jesus is unto us Salvation. We are in Him and He has become Salvation. It is not a thing, but a living union with a Living God. Thus, Jesus saved them out of Egypt.
Second, in Jude 5, Jude then expresses this idea of exodus in Jesus. For instance in 1Co 5:17, Paul says Jesus is our Passover Lamb. And in John 14:20-like fashion, the people indeed entered into the dead lamb and they put the dead lamb into them. So when death passed over, it saw them as already dead in the lamb. Thus, Jesus saved them out of Egypt.
This is of course, Jesus, as we enter into His death and fully partake of His death into us. We are crucified with Christ (Gal 2:20). We are raised together (Col 3:1, Eph 2:6). We no longer know Jesus according to the flesh (2Co 5:16). Nor did they know each other that way, because of this union.
Third, Jesus associated himself with the Passover-exodus concept in John 6 by asking people to eat His flesh and drink His blood. And at the Last Supper, Jesus gave the disciple the same – His flesh, His blood. Jesus had queued up the Passover reality, where He saves them out of spiritual Egypt. Thus, Jesus saved them out of Egypt.
Fourth, Exodus 4:22 also points to Jesus as Israel, My Son, My Firstborn. When God said this to Moses, He spoke of a multitude of people, yet He sees them as one Son. We all know how Paul speaks of believers as the members of Christ’s body. His Act 9 realization that attacking a Christians was attacking Jesus never left his communication. Thus, when Israel exited Egypt, God saw them as one corporate Son. Out of Egypt I called My Son (Mat 2:15 and Hosea 11:1). Thus, Jesus saved them out of Egypt.
Therefore, I think it is quite clear that Jude is speaking this way of Jesus as their common salvation, in Whom they are. And that the people sneaking in are trying to break that union where Jesus is Personally our salvation and righteousness. Jude 4 literally says the are “changing the fundamental location / thesis”. How are they breaking that union< They are doing it by taking the reality out of the realm of spirit and life and placing into this sense-based system or religious rules, ritual, sacrifices, Sabbaths, and so on. By the time Jude was written, I don’t think the church leadership was thinking of Temple Judaism as a Christless religion different from them; rather I think they saw them as rogue, very much lost in sense-based realm, even an abomination in the Isa 66:3-sense:
Isa 66:3 ESV "He who slaughters an ox is like one who kills a man; he
who sacrifices a lamb, like one who breaks a dog's neck; he who
presents a grain offering, like one who offers pig's blood; he who
makes a memorial offering of frankincense, like one who blesses an
idol. These have chosen their own ways, and their soul delights in
their abominations;
Note that all the sacrifices are allowed in the Mosaic Law. So in my opinion, whatever it is worth, I think there is a case to be made for “Jesus” as the correct variant.
Fifth, I think this understanding of Jesus as Salvation, in Whom we exist, explains why Jude 6 follows. If Jesus is our Source of Salvation, Himself in Whom we abide – Christ as our life in Col 3:4, then those who do not guard and maintain Him as Source end up facing a great judgment. Thus, the “messengers” of Jude 6, could easily be interpreted to mean people such as “Adam and Eve, who were kicked out of the garden followed by that sad refrain in Gen 5 of “and he died…” until that entire race of Adam was judged by the Flood, which I understand “ζόφον zophon” to be referring to the Flood. Thus, this of Source = Jesus Salvation unto us as opposed to working for it, is the transition from Jude 5-6.
Sixth, if the Flood is intended in Jude 6, then it dovetails perfectly with Jesus having saved a people out from the midst of the land of Egypt. The two stories are very similar in that they share imagery remixed. For instance, both the houses in Egypt and Noah’s wooden boat have a covering that is specifically applied. Both also have distinct openings that had to be entered and exited from. Both enter into the opening towards a death to something they were leaving behind. Both exited into something new. In both stories, the old was plundered: the Egyptians gave Israel treasures, Noah had the animals. They both went from a place below to a place above. Egypt is low and Mt Sinai is high It is the same with Noah’s boat which came to rest on mountains. (I know some of these sound simplistic, but I think they are intended pictures that almost go without saying). And of course, who could miss the parallel between Noah and Jesus as “one man saves the world.” One man’s name means Rest, and Jesus, the Lord of the Sabbath gives our souls rest when we are in union with Him like an oxen team with a crossbeam sized yoke. Thus, Jesus saved them out of Egypt.
And lastly, I will finish with the most obvious point as to why I think it is Jesus, specifically the name: Yah-saves. Inherent in the name of Jesus is the Father saving us (John 14:6, Heb 1:3). I could go about Moses and others, but I think Jude’s audience knew all this by just skimming the great pond with this letter.