Rapture and Revelation

Dr. Jeannie discusses the Protestant doctrine of the Rapture and Revelation. In Ch. 8 of Revelation, the seventh seal is opened, which begins a period of intense tribulations. Seven trumpets are blown resulting in dramatic changes and suffering among people. Why does God send the tribulations? Is this hell or is it punishment on earth for those destined for hell? Will anyone escape these tribulations? Who are the two witnesses who are sent to earth? Is there such a thing as the rapture? Will some people be taken up and spared the suffering of the end times?