This is the document most christians try to claim as non-bias historical fact that jesus was the messiah and performed the miracles. But there are a few flaws with this thought. First most historians believe that the portions we find written about jesus having any miraculous powers were probably added in by the catholic interpreters to further the credibility of their religion. And the second is that on the off chance Josephus had actually written that and thought it to be true history, then why would he himself not be a christian?
http://www.truthbeknown.com/josephus.htm
http://www.truthbeknown.com/josephus.htm