All around us people are claiming to speak from God. Almost everyone has witnessed the charismatic television evangelists alleging a vision or prophecy has come to them from God. Many people have also been exposed to the Third Covenant being distributed by Mormon adherents. But can these latter day revelations be trusted? Is God still speaking to us today? Is He speaking to anyone? Jude most succinctly answers this question,
"Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith which was once for all handed down to the saints. For certain persons have crept in unnoticed, those who were long beforehand marked out for this condemnation, ungodly persons who turn the grace of our God into licentiousness and deny our only Master and Lord, Jesus Christ. Now I desire to remind you, though you know all things once for all, that the Lord, after saving a people out of the land of Egypt, subsequently destroyed those who did not believe." (Jude 3-5)
Jude warns of those that will creep in and teach a different faith, but the message of confidence that he bestows on Christians is that the faith has been delivered - handed down - once for all. Therefore they should be reminded that they know all things once for all. In other words, there is nothing more to hand down and nothing more for them to know with regard to the faith that saves. In the same way the recipients of Jude's letter can know all things because of this teaching, so can we.
The faith can be described as that body of belief that was taught and preached by the apostles, by which we understand God's plan and His will. This was a common expression among first century Christians. In his great record of church history Luke describes obedience to the faith (Acts 6:7). Elymas was said to oppose the faith (Acts 13:8). Paul preached to Felix concerning the faith (Acts 24:24). In His letter to the Galatians, Paul makes claim to preaching the faith (Galatians 1:23). Paul writes to Timothy that some will fall away from the faith (1 Timothy 4:1). The faith is an idiom describing Christianity as a movement in the first century.