http://www.stmarycoptorthodox.org/7- the great tribulation.htm
What do you know about it?
from this article (?) I think it is important to understand parts in revelation for salvation..
"Instruction of the catechumens about the coming of Antichrist was a major component of the Catechism given to new converts. The Church believed that knowing these things is essential for salvation,"
That is from near the end of the article (?)..