"We ourselves heard this voice that came from heaven when we were with Him on the sacred mountain. And we have the word of the prophets made more certain" (2 Peter 1:18-19).
General and special revelation are terms referring to how God communicates with man. General revelation is God revealing Himself through creation; special revelation is direct, supernatural revelation.
The incarnation was a special revelation: "In the past God spoke to our forefathers through the prophets at many times and in various ways, but in these last days He has spoken to us by His Son" (Hebrews 1:1-2).
The Scriptures are a special revelation. The writers were led by the Holy Spirit to communicate precisely what God intended: "Above all, you must understand that no prophecy of Scripture came about by the prophet's own interpretation. For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit" (2 Peter 1:20-21).
The Holy Spirit provides special revelation to those who have received certain spiritual gifts; for example, the gift of prophecy. Some believe these "sign" gifts ended with the closing of the canon; others believe the gifts are still in use today.
All cults are founded upon the belief that they have received special revelation. This generally takes the form of a teacher or "prophet" who is supposed to have received special revelation. Many times these groups claim to believe the Bible "so long as it is translated correctly." By saying this they indicate that they have reinterpreted the Bible to fit their own heretical belief-system. The Holy Spirit warned us that this would happen: "For the time will come when men will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear. They will turn their ears away from the truth and turn aside to myths" (2 Timothy 4:3-4).
Any "new" revelation must always be tested by the word of God. Solid grounding in the Scriptures, along with a knowledge of the tools and methods of sound Scriptural interpretation, should be a priority of every Christian. Failure to equip oneself will result in an ineffective witness, and will increase the possibility of being led astray by false teachers.