It's one thing to know the words of God in the Bible-- its another thing to know the person of the Living Word, Jesus Himself, that Author. If knowing the words of the Bible meant having a good relationship with God, the Pharisees would have rocked-- they had the whole thing memorized! The Bible is meant to bring us into conversation and relationship with God.
All truth is not created equal. Not every truth has the same weight. Faith, hope, and love are all weighty truths, but the greatest of these is love. The Bible isn't always true. The devil knows and uses the Bible. The Bible in the hands of the Spirit is true. We need discernment to walk in the truth and to hear the Word of God which brings life.