In these verses, Jude is thoroughly condemning the heretical false teachers of his day by expounding on the truth of judgment and the truth of punishment for the ungodly. As such, they serve as a great reminder for us; a reminder that God, in fact, IS going to judge humanity and punish the wicked, we must understand that humanity will be judged for who we are as well as what we do, and, since judgment and punishment are guaranteed, the need for evangelism is urgent.