Jesus stresses the importance of hearing his word and acting on it so that we may bear fruit. After you hear the word preached in the homily at Sunday Mass, do you act upon it at all? Or your conscience tells you that you should do something and you only go as far as agreeing with it? The Protestants claim that we are justified by faith alone, while we Catholics believe that works are necessary too. In reality, if you truly believe in God, good works automatically follow ~ you can't help it. At any rate, whether you act or not after hearing the word of God makes the big difference. It results in the difference between being a nominal Christian and being a true disciple of Christ.