"Beloved, while I was very diligent to write to you concerning our common salvation, I found it necessary to write to you exhorting you to contend earnestly for the faith which was once for all delivered to the saints..." (Jude 3).
The original Greek word hapax translated "once for all" means that it is "of perpetual validity not requiring repetition" (Vine, pg. 819). The faith delivered to the saints is of such quality that it is complete ("perfect" James 1:25) and will not tolerate repetition or alteration. This means that any "revelations" since the faith was given “once for all” have not come from God but from the inventive minds of men. It further means that those who claim the revelations and those who believe them are condemned. The warning is clearly given, "Whoever transgresses (goes ahead) and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son" (II John 9).
We must recognize and respect the significance of this word translated "once for all."