“But I want to remind you, though you once knew this, that the Lord, having saved the people out of the land of Egypt, afterward destroyed those who did not believe.”
God’s attitude toward apostates is clear from the Bible. Jude gives three examples from the Old Testament of God’s judgment on those who opposed His authority:
Unfaithful Israelites in the Wilderness(v. 5)
Sodom and Gomorrah(v. 7)
But I want to remind you,
Verse five deals with unfaithful Israelite sin in the wilderness at Kadesh Barnea. (Peter in his parallel passage does not use this illustration.) God wants us to take heed of Old Testament examples, for what is germinal in the Old is terminal in the New Testament. Old Testament warnings are useful for New Testament believers. All three examples are from the Old Testament (the wilderness judgment in Numbers 13and 14 for Jude 5, Genesis 6 for Jude 6, and Sodom and Gomorrah in Genesis 19 for Jude 7). All three examples are historical, not mythical or fictitious. They actually happened.
The word “but” is a right-about-face word. Jude made a strong decision after careful deliberation (Greek) to remind and warn his readers that the judgment of the “ungodly” of verse 4 is the same judgment of the Old Testament. He did this by reminding them of Israel’s rebellion in Numbers 13 and 14. Learning something once is not enough. We need to apply truth over and over if it is going to stick to our souls and enter our experience.
though you once knew this,
Jude does not tell his readers something they did not know. They knew it but it had faded from their minds, making them vulnerable to apostasy.
Jude gave the example of the Israelites, but so did Paul (1 Co 10) and the book of Hebrews (3-4). Many Israelites did not believe God to enter the Promised Land. It was a form of rebellion.
Jude’s readers came to a full understanding of this example. The Greek indicates that they knew it once and for all. That truth is still there in their thinking. The “this” is divine doctrine–God’s Word.
The ability to remember doctrine is crucial to Christian living.
Remembrance is crucial in Christian thought. We forget so quickly. That is why “precept must be upon precept, precept upon precept, Line upon line, line upon line, Here a little, there a little.” Is 28:10
Beloved, I now write to you this second epistle (in both of which I stir up your pure minds by way of reminder). 2 Pe 3:1
For this reason I will not be negligent to remind you always of these things, though you know and are established in the present truth. Yes, I think it is right, as long as I am in this tent, to stir you up by reminding you, knowing that shortly I must put off my tent, just as our Lord Jesus Christ showed me. Moreover I will be careful to ensure that you always have a reminder of these things after my decease. 2 Pe 1:12-15