Jude was most probably a younger half-brother of our Lord Jesus. He identified himself as the brother of James, the eldest of Jesus’ half-brothers (Matthew 13:55-56; Galatians 1:19).
When we are surrounded by lies we need to be reminded of the truth. Otherwise we risk being pulled away from Jesus and becoming a spiritual danger to others.
As Jude warned against the dangers of abandoning the true gospel and embracing false teaching, he gave two examples: angels who became demons and two sinful cities which were destroyed.
Opposition can be paralysing. We can be like frightened animals, hiding and motionless while danger threatens. But that was not the example of Jesus or the Apostles.