Richard Lischer suggests that one of the ways to organize a sermon is around a “master metaphor”—that key image on which the sermon’s progress and structure can hang. More often than not, the scripture passage itself gives us the master metaphor.
If it’s difficult for listeners today to connect with the Bible’s injunctions against idolatry because our own idolatry looks so different, the metaphor of God as “fountain of living water” being forsaken for self-dug, cracked cisterns is striking.