We don't have a SINGLE written document from the people who knew Him or saw Him FIRST HAND... everything (including the gospels) was written DECADES after Jesus died... by people who never even met Him
Never met God?
Are you saying Moses never met God?
None of the prophets met God?
The Holy Spirit working in us, is God working in us. No Word of God would be enough, because knowledge comes by Faith, through the Word of God we do have. It is the human understanding and additive interpretation of man that causes differences of opinion. The very fact that we can freely accept God's Word, instead of freely accepting our own understanding, points to the fact that differences is the point of error, not the narrow understanding of the Bible itself.
Just like no one should be forced to accept human understanding which leads us into error, God does not force us to accept what we do read in the Bible. The problem is the "lack of coercion". You point out that God did not give us enough information. Yet information itself is a form of coercion.
If we knew everything, we would still reject it, but it would bind us to the truth, instead of letting us have the Faith that God seems to require. God allows freedom, instead of the demand, having all the facts would impose upon us. Remember it is truth that sets us free, not the fact of knowing everything.
We have the truth in God's Word. What we do know
is enough to set us free from thinking we know everything.