Why , after 2000 years do we still not agree on the Bible?

For many years my own  typical conditioned response, reasoning from out of my inherited theological framework, to any point or opinion not consistent to my own, was ‘But the Bible says!‘

"...but 'my way' is the only 'right' way!'

I was so taught and was attempting to ‘micro manage’ Bible truths and principles without considering the overall larger message of the Bible. The larger plan and macro framework!
It was very much like building a puzzle without the picture on he outside of the  box!
My current position however, when faced with sometimes difficult to ‘explain’ scriptures is to first ASK,and ANSWER this vital question;
‘Who is Jesus Christ,the Son, and what has God the Father done to humanity in and through Him?”
The ANSWER to this question is the macro plan and picture!The overarching paradigm of the entire Bible from Genesis to Revelation!
It is the picture on the outside of the box of a puzzle, without which you cannot successfully put together the pieces to form  the picture!
This has become for me the true interpretive key to unlocking what the entire Bible is all about, namely the Mystery: of both the Father and the Son and their intention to include mankind in the life, the love and the glory of the Trinity.
For myself, I know that I need to interpret every verse in the Bible in the light of this ANSWER, otherwise I am missing the point and  message of the Bible!
What is your ‘interpretive key’ when reading and attempting to make sense of the Bible?