When we want to know the condition of a car, it is not just the externals that matter.
Neither will lifting up the bonnet tell us anything about the condition of the engine.
It is only by starting the car and running it on the road that we will know what is the condition.
Similarly the 1st reading tells us not to just listen to the Word of God but also to do what it tells us to do.
To listen to the Word and not obey it is like looking at your own features in a mirror and then forgetting what you looked like.
It also means that we have to listen to what we are saying to others.
And the 1st reading tells us to be quick to listen but slow to speak and slow to rouse our temper, for God's righteousness is not served by man's anger.
The Word of God will do away with all our impurities and bad habits if we allow it to.
And we will know if we are listening to the Word of God and putting it into action when we listen to what is coming out from our mouths.