It is the Bible itself that convinces me.  It reads like no other book, written over centuries with an overarching theme and inherent consistency with a real focus on Jesus Christ, the Son of God, and his death on the cross for the sins of mankind, to restore the willing to a right relationship with the God whom mankind had rebelled against. 

The prophecies in the Bible have been consistently fulfilled with more to come.  I read someone recently that doesn't believe the Bible is God's book, but based on his research does believe in a cabal who are using some of the prophecies in the book of Revelation as something they want to bring about - things like the One World Ruler (the AntiChrist) and his mark which you'll have to have to buy or sell.  Interesting.  If he is right, they sure sound like a dreadful group. 

My dad, also a Christian, was a young man when those studying prophecies predicted that Israel would become a nation again.  At the time such a thought seemed impossible, but here we are.  Jerusalem was also prophecied to be a cause for conflict among nations, etc.  

Even if you don't believe it to be God's book, as a book that has altered large civilizations it is worth a read, imo.