About Jude's letter

Jude's letter is a message to Christians about false teachers, who were teaching wrong things. Those teachers said that they themselves were Christians. But they were very dangerous, because they stopped some people from obeying God. God is very angry with false teachers like that, and he will punish them.
In verses 17-23, Jude tells the Christians that they must be very careful. They must continue to believe the right things that God's true message teaches. They must continue to love God and other people. They must try to help their friends who have believed the wrong things.
We do not know which Christians Jude was writing to. Nor do we know when he wrote his letter. But Jude's message is very important for all Christians at any time.