I saw the program on Manna-Fest about Perry Stone's belief that the rapture will be like a bomb effect and many will be in the dark. While this may be exactly what happens, there is one thing for sure - if many people are unsaved and their loved one disappear right in front of their face (and don't lets forget in part of the world it won't be DARK, the SUN will be shining) - then many thousands will KNOW what happened. They may not have electricity, etc., but when half the world is actually dark, the other half has sunshine (unless at the same time, God darkens the sun, which He could very easily do.]
 
Rene