Part One of Contending, Contextualizing, and Seeking Converts.
Jude 3 says this, Beloved, although I was very eager to write to you about our common salvation, I found it necessary to write appealing to you to contend for the faith that was once for all delivered to the saints.
Jude, the half brother of Jesus, is very open with his readers here. It was his desire to write to them about their common salvation, but instead, he found it necessary to change course in his letter in light of the opposition he discovered to be present among his readers. As evangelical Christians, it is important that we cling to important truths about the Bible. The simple fact that we refer to ourselves as evangelical Christians, rather than simply Christians, is a sign of the importance of giving some definition to what it means to be evangelical.
In many circles, the term Christian is even being dropped in favor of terminology such as Christ Follower. Why? Because the terms themselves have become so ambiguous that in, the estimation of many, they no longer represent the truth in which they were rooted. So, for instance, those who claim the Christian faith must identify themselves as mainline, evangelical, and/or born again, etc... An evangelical understands that being a Christian requires regeneration, but to the world at large, the lack of understanding about these terms has required further explanation. Even last week, evidence of this desire to define evangelicalism was given in the release of the Evangelical Manifesto, which is the attempt by some scholars and well known evangelicals to define what evangelicalism is and is not.
In light of these things, if we are to be missional, before we can ever talk about our common salvation we must be willing to contend for the faith that was once delivered for all the saints.
Unless we properly define the faith, it is impossible to have an adequate discussion of that faith. Jude knew this, and illustrates it well for all of us to model in his epistle. According to Tom Shreiner, the faith here spoken of here does not refer to trusting God. In this context, "faith" refers to the traditional teaching that was to be safeguarded. Paul and Luke also mention the "faith" on several occasions when they have in mind the message of the gospel (Gal. 1:23; Eph. 4:5; Col 1:23; 1 Tim 3:9; 4:1; 6:10, 21; 2 Tim 3:8; Acts 6:7; 13:8).
The faith of which Jude spoke was and continues to be the truth of the gospel. The truth and purity of that faith was of such great importance to Jude, that he turned from his original intent, and wrote a different letter. In this letter, he encourages his readers to contend for the faith. The word contend in the New Testament means exactly what you probably think it means; fight on behalf of the faith. Eugene Peterson, in The Message, says fight with everything you have. In fact, in a brief survey of modern translations (I only checked about 5), I could showed no translation that uses any word other than contend.
It is possible that this word has its roots in either military engagement or athletics, but the truth of that is not verifiable, neither are those illustrations necessary to communicate the earnestness in the message of Jude. Jude meant for his readers to fight for the truth in the face of some who had gained admission to the church and were perverting the truth of the gospel and the grace of God.
If we are to be truly evangelical, as we must not only share the Good News of Jesus, we must define that Good News and constantly fight for the purity of that definition within our churches. Will Metzger has said that truth is the measuring stick for evangelism, but it is also the measuring stick for evangelicalism. Without absolute truth, we are just liberals.
In the Affirmations and Denials of Together for the Gospel, gospel is affirmed this way:
We affirm that the Gospel of Jesus Christ is God’s means of bringing salvation to His people, that sinners are commanded to believe the Gospel, and that the church is commissioned to preach and teach the Gospel to all nations.
Affirmation of this Gospel, however, is not a definition of the gospel and it is not enough. John Stott says that the Good News is this:
That Jesus Christ died for our sins and was raised from the dead according to the Scriptures, and that as the reigning Lord he now offers the forgiveness of sins and the liberating gift of the Spirit to all who repent and believe.
This may not be a comprehensive definition, but it is pretty good for a concise statement about the truth of the gospel, and is a statement with which I readily and heartily attach myself. It is this faith that we must contend for. The gospel of social activism or environmentalism or prosperity is not the faith that was once for all delivered to the saints. Those instead are messages that have recently been delivered to itching ears (see 2 Timothy 4:1-3).
If we are to be truly evangelical, which is a word that comes from the transliteration of the Greek word for gospel, then we must be gospel people and we must have such a firm grasp on the concept of gospel that we can and are willing to contend for it. If we preach a false gospel, a fake gospel, a wrong gospel, we have ceased to be evangelical and have become accursed (Gal 1:8), to use Paul’s language. A false gospel is false hope and offers to no one the promise of salvation, only one of delusion and confusion. Salvation from anything other than our sins is little more than self-help, and no one will ever help themselves out of their sins and into God’s grace.
Missional people are evangelical by definition. Evangelical people are gospel people by definition. The gospel is the root of all that is Missional and evangelical, and the truth of the gospel must be fought for whenever it is questioned; not because the truth changes, but because only a truly taught gospel can bring salvation to sinners.
 Schreiner, Tom. The New American Commentary: 1,2 Peter, Jude. Nashville, Tennessee: Broadman and Holman Publishers, 2003, 434.