Jude is continuing his rant - warning readers of people who are no longer rooted in Jesus being Lord. In verses 12 and 13 he basically says 'These people don't bring anything good'. They are bad influencers, and if they get into positions of leadership they make bad leaders. By looking at these examples of what is bad, we can think of what actually makes for a good, positive influencer.
Jude's spotlight on bad leaders shows that they take care of themselves, when they are supposed to be helping others. They are like 'clouds without rain' - in England we might be glad of that, but of course in drier climates the presence of clouds brings hope - but then disappointment if no rains come. Another image is the fruit tree - a tree that bears no fruit again is of little use. Worse is a tree that is up-rooted! Notice how Jude describes it a 'twice dead' - no fruit and uprooted, doubly of no benefit.
Turning to the waves: they can be all froth and bubble, but of course they just dissipate without bringing anything useful. Finally Jude looks up to the stars - points of navigation for ancient travellers, but wandering stars impede navigation and lead you to be lost and nowhere.
In summary bad leaders take for themselves, do not bring anything good, are blown around, are all froth and bubble, and ultimately lead you nowhere. All that is the opposite of how God wants us to be in Christ. You might think "but I'm not a leader", but we should remember that in Christ we can all influence people. That makes us a leader whether we like it or not!
So let us ask ourselves whether we are going to influence people positively in Christ, becoming a Jesus-like influencer. Are we someone who brings Jesus into a scenario by the way we are, the things we do and say? Are we people who hold steady in a crisis, and point people to God's grace? Do we contribute to a positive atmosphere in a workplace or group? Do we show people a better way, the Jesus way, in fact showing people Jesus? Hence our key question and challenge:
Key Qn: [IN] To what extent are you helping others to serve God better?
Challenge: Get someone to pray with you to be a greater Jesus-like influencer