How to Contend for the Faith

Jude not only warns Christian assemblies of the danger of false teaching and teachers who have slipped into the churches but he also gives a summary of how to combat them. He does so in the command "keep yourselves in the love of God. He relates 3 ways of doing this. Jude 20-21
20f But you, dear friends, by building yourselves up in your most holy faith, by praying in the Holy Spirit, keep yourselves in the love of God, looking forward to the mercy of our Lord Jesus Christ to eternal life. LEB

Jude 20-21
20 But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit, 21 keep yourselves in the love of God, waiting anxiously for the mercy of our Lord Jesus Christ to eternal life. NASB

New English Translation " But you, dear friends, by building yourselves up in your most holy faith, by praying in the Holy Spirit, maintain yourselves in the love of God, while anticipating the mercy of our Lord Jesus Christ that brings eternal life." Jude 20f

Paul in his letters to the church in Corinth and John is Jesus letter to the 7 churches give us concrete examples.