We have disagreements because we INTERPRET what we read in different ways. This happens within the various Prot. denominations as well. So, as I look to others for a deeper understanding of what I read (and not just biblically), I look to the interpretations of a 2000 y.o. Church to assist with my thoughts.
I can't believe that I am the sole authority since I am not infallible. If we're guided by the Holy Spirit, than we cannot all be right. Could this be ego? I don't know.
It borders on condescending when you suggest that we don't read the bible and instead look solely to others for what to believe.
You have to know what God's word says before you can discern between someone's opinion and the facts written in His word. When I read 1 Corinthians 15:1-4, it tells me what the gospel is. Romans 1:16 tells me that I have salvation if I believe the gospel. When I read Ephesians 2:8, it tells me I am saved through faith and that God gave me salvation as a gift. We can argue and discuss all things about our faith but God's word clearly states that we are saved by faith plus nothing. I don't care what church you attend, if they don't teach salvation by faith only; you are in the wrong one. No one church holds the truth.