Listen to the last twelve minutes of John Piper’s January 4, 2009 sermon via this link. The entire sermon is excellent and quite unusual; these last twelve minutes focus on two topics: First, the need for our minds to be engaged with the Word in order to live lives worthy of God’s calling and in order to fight Satan effectively; second, the responsibility of fathers and husbands to apply the Word to issues in the family. Very powerful. This section begins 35 minutes and 50 seconds into the sermon.