In this first part, Marty observes that much of his life as a Christian involved a "personal relationship with the Bible" but not much of a "personal relationship with Jesus". The transition to an intimate conversational relationship with Jesus hasn't been easy. Marty shares what has helped him in making this shift.
To think Biblically about this idea of hearing God's voice, compare John the Baptist with the religious leaders in Jesus' day.
In John 1:32-34, John the Baptist reports that the only way he was able to identify that Jesus was the Son of God was that "the one (ie, God) who sent me told me". The quotation marks in verse 33 are very important! John is reporting what he heard from God (and it didn't come through Bible study!).
Now, compare with the Jewish leaders in John 5:33-47. These guys "diligently study the Scriptures" (v. 39) but, according to Jesus, "you have never heard His (the Father's) voice" (v. 37). As a result, they were unable to understand who Jesus was or to come to Him for life.
Our conclusion is not to downgrade Bible study but to upgrade the intimate conversational relationship with Jesus. The Bible remains our "authoritative guide for faith and practice". But, we realize that the primary practice that it points toward is hearing God's voice and obeying.
Learning to do this is the journey we are on.