I don't know whether Criswell believed his own predictions or not. I only know that he was wrong. A lot.
An excerpt from the January 11, 1973 Oakland Tribune (Oakland, CA) containing Criswell's prediction for our last day on Earth appears below.
His rubicund countenance aglow with camaraderie, Criswell said the predictions in [his book] were prompted by a ghostly visitation of Nostradamus, the 16th century prophet who reputedly had correctly predicted the founding of America and World Wars I and II, not to mention flights to the moon and - hold your hats - the final date of this earth, August 18, 1999.
Sorry about the soapbox rant today. Sometimes the paleo-future can get kind of heavy. Consider my anti-psychic-powers posts to be public service announcements interrupting our regularly-scheduled shenanigans. Jet packs, meal pills and rowbuts will return tomorrow.