The Call to Discipleship: The Abiding Principle

What is the difference between a believer and a disciple? Here in John 8:31-32, Jesus gives the first of six differences. These six principles are the "tests" Jesus gives us to determine if we are truly His disciples. This first principle, The Abiding Principle, is the foundation for the remaining five. What does it mean to "abide" in Jesus and His word?