As a Christian, in my life the highest authority is the Bible as like as many Christians. Some people in the past use the word Sola Scriptura which means Scripture alone. Scripture or the Bible is the source of authority of all and we must read it day and night as what the Bible says in the Book of Joshua. But as a human sinner, we must know also that by reading alone the Bible or the Word of God cannot save our life. Yes it can be talk to us and convict us in our sins that we have committed before God to repent from it but conviction is not an end to be saved. We need to accept Christ as our personal saviour by faith because we cannot see Him anymore. Salvation and justification comes by faith alone and this is all by the grace of God. We are all deserving to be thrown in hell because we are sinners but by the grace of God, he saved us. We received what we did not deserve which is salvation.