“But you, beloved, yourselves being built up in the most holy faith, praying by the Holy Spirit, keep yourselves in the love of God, receiving the mercy of our Lord, Jesus Christ—eternal life.”
He begins the exhortations with guides for spiritual health within the congregation. We are to build ourselves up in the faith. This is different than the puffing up that the false teachers were doing. But building up is done through teaching, Bible study, fellowship, worship, and prayer. It is the laying of a sure foundation upon which our faith can be solidly built.
Secondly, we are to pray by the Holy Spirit. It is a reminder of what Paul teaches us that the Holy Spirit is a guide to our prayers and it is a reminder the Holy Spirit is the third part of the Trinity and an integral part of our salvation, actively working in our lives through the process of sanctification.
Thirdly, we are to keep ourselves in God’s love. Jude is not trying to replace God’s grace, but is linking grace and love together as one goes hand in hand with the other. And he is not suggesting that those who are truly saved can lose their salvation, rather he is saying that when we walk in disobedience, we earn God’s rebuke; we are to walk faithfully, striving for a “well done, my good and faithful servant.”
And Fourthly, we are to rest in the final salvation that Jesus Christ has assured. The judgment of God against unrighteousness means salvation for those who have been saved. What does the mercy of God look like when it is applied to a person’s life? It fully manifests itself in eternal salvation—eternal life in the presence of God himself. What more could we hope to ask?