When I get unusual emails, I always check out snopes.com to see if they've proven it wrong.
When I got this one, I again checked Snopes & they quote directly from the book of Revelation: there's no mention of him being in his 40s or a Muslim.
I don't like Obama at all...but I'm not gonna forward an email like this just to get a reaction.
Check it out for yourself:
http://www.snopes.com/politics/obama/antichrist.asp