'Reasons" is a tricky word. Some people would say they have reason to believe it because their parents are decent people and told them it's all true. What kind of reasons are you looking for?
The bible must be considered for what it is. The book doesn't claim to be a single blank book that was commanded by God to be passed from prophet to prophet from Adam to John, while each adds new revelations from God throughout the ages. Many authors of books that are included in the Bible were simply writing songs, poems, or letters. Some of these were likely meant to be dispursed freely, while others were intended for a particular audience and the author probably never dreamed that they would be used as we are now. The men were also individuals. They held different opinions, different perspectives, and were impressed by different things. Do I believe that the writings were inspired? Sure. Do I believe that they are completely historically accurate in every little detail, and that centuries of retranslation and recompilation in no way introduced error? No. I don't think it is fair to use the Bible as a history book. Many of the authors never intended it to be historically complete. Its purpose is religious, and historical information therefore depends largely on the perspective and knowledge of the author. In my mind it is then better to say that the Bible is religously complete, and that any useful historical info we can glean from it is simply a nice byproduct.
I am looking for whatever reasons you believe it it or you believe it isn't. Your reasons don't have to agree with mine. I am trying to be "objective" to help myself facing the "belief" that I once "believed".
That was an example. It might be a "good" reason for others, but I won't take it as a reason to support my own belief. Of course, some "scientific" or "logical" reasons are acceptable to me, but "pure faith-based" reasons are not what I am looking for.