Jude encourages us to be on our guard against false teachers. On our guard because they lead people into sin and we do not want to do what God hates. On our guard because they will face the judgment of God and we do not want to perish in God’s fires with them. On our guard because they do not have the Spirit of God even though they claim to be led by him. How then are we to respond to this threat?
The answer can be found in Jude 1:20: building yourselves up in your most holy faith.
This is the faith that comes from God and is taught by the apostles, the faith delivered to the saints and written in the Bible. We do not respond to false teaching by tracking down these individuals and making sure they are excommunicated, but by building ourselves up so that we are not led astray. As individual believers we must grow in our knowledge of what is good so that we are less vulnerable to the attraction of the false gospel. We must make the effort of learning the right doctrine and walking in holiness.
That is not to say that church discipline and excommunication has no place—we should expect our elders and pastors to defend the teaching of Scripture against those who pervert it. But the letter of Jude was written to a church and not only to its pastors. Contending for the faith is a job for all of us.
20 But you, beloved, building yourselves up in your most holy faith and praying in the Holy Spirit,