Respectfully, I think that when one approaches Christianity for the first time it's quite necessary to look at the historical aspects of it.
How things were at the beginning, what was believed and practiced, and how they changed.
If one wants to become a Catholic, or a Lutheran, or one of the major branches of Christianity, you don't just walk in and sign a sheet. You have to go to classes. You take the time and learn and study and see what it's all about. So you don't see people one day announce "Hey I became a Lutheran today." My perspective is that you DO, however, just announce one day that you're born again. There's no long term study associated with it, it's made to be a very simple thing - just give yourself to Christ, publicly read a few words and you're in, you're a saved Child of God.
I don't mean to make one sound better or more appealing than the other, but those are very different approaches to take to Christianity. And this is ME speaking from my own experience now, I personally want to know all the history, what was believed, what was changed, what was discarded, etc. before making up my own mind which path I'm going to take.
So how this all ties in with your post - when you say it's hard to you to accept anything outside of the Bible, you most likely have not looked at historical Christianity when there was a time when there was MORE than just the Bible to consider.
I understand. oy, this is going to be a lot of research on my part. Still, I believe the bible was inspired by God. Yeah I know there are more books than the books of the bible, but I think God chose those books because we would need them for guidance. So, anything outside them must be prayed over and validated by the Holy Spirit.