Immediately after greeting his readers, Jude goes straight into his reason for writing his letter (Jude 1:3-4). He had originally intended to write about God rescuing them from sin and death through Jesus the Messiah, who died for them and rose again on the third day (v. 3). But he received news that caused him to change his purpose. So, instead of writing about the salvation that he and his readers share, Jude writes to encourage his readers ″to contend for the faith that was once for all entrusted to God's holy people″ (v. 3).

The reason for his urgent message (and I hope you can sense his urgency) is the stealthy infiltration of certain people into the believers' midst (v. 4). These people mingle with everyone, hiding their true identity and their purpose for being there. Jude is determined to expose them for who they are and for the danger they pose to Christians. The first step in contending for the faith is to recognise who the enemies are and their tactics.

Jude does not mince his words: these are ungodly people (v. 4). He uses the word ″ungodly″ six times in this brief letter (vv. 8, 15, 18). These are people who have rejected God and His authority in their lives (v. 4). And this is clearly seen in their sinful and irreverent acts. They distort the grace of God and use it to justify their sinful lifestyle in sexual immorality, drunkenness, depraved behaviour, and so on (vv. 4, 7, 8, 16). They might have said to Christians: ″God loves you and Jesus has died for all your sins. He has set you free. It does not matter what you do with your body. God's grace will cover your sins.″

By perverting God's grace and indulging in their immoral lifestyle, these ungodly people are in fact denying ″Jesus Christ our only Sovereign and Lord″ (v. 4). They reject the authority of Jesus Christ, the only Lord and Master, and turn away from His ethical demands on their lives.

For Jude, there is only one end for these ungodly people: they will stand under God's condemnation (v. 4). This theme of condemnation will make up most of the body of the letter, in which he cites from the Old Testament (vv. 5-8, 11), Jewish works (vv. 9, 14-16), and the teaching of the apostles (vv. 17-18) to support his claim.

So, right from the start, as Jude warns his readers about false teachers in their midst, he also reassures them that these ungodly people will not escape God's judgment. His readers must reject these people and their teachings and way of life. They must continue to acknowledge the authority of Jesus Christ, their only Sovereign and Lord.