James 1-22

Be doers of the word, and not hearers only deceiving yourselves. 

For us to be doers of the word, we have to let in sink in.  We can hear things but not really listen, and listening is the key to absorbing knowledge.  God says to meditate on the word because He knows we may not absorb the meaning the first time through.  We may have to speak it out loud and focus until we receive understanding.  The word of God is like a seed planted in us, sometimes it needs time and nurturing to grow.