Thy word is truth. So our holiness, our Christlikeness, our moral newness is torpedoed if Satan takes the word away from our hearts and minds. A persistently fruitless hearer of the word cannot be a disciple of Jesus. Fruit does not make a tree good. Fruit does not give life.
Fruit is a sign of life and reality.
Good and bad trees are known by their fruit. Bad fruit or no fruit means bad tree or no inner reality. Therefore fruitfulness is essential to being a true disciple of Jesus. And since the abiding word is the key to fruitfulness, discipleship is at stake if Satan takes the word away. If the word is taken away from our hearts, we cannot be followers of Jesus.