I remember being in Texas a few years ago, in a place where the country was very dry and parched. In that dry country there is a beautiful river that springs right out of the ground. It flows along; and on both sides of the river you find life and vegetation. Grace flows like that river; and you can trace its source right up to the very heart of God.
The analogy works perfectly. First he begins, “I remember”. He promises a story and vouches for the truth of it. Texas likely seemed exotic at the time and place of Moody’s audience: thus the story would have built in interest.
Second, he tells the story with few words: He paints the picture and moves on. Many writers and preachers mar the story with too much telling.
Third, the story had a kind of pathos and beauty: a river springing from the dry, hard ground brining life.
Fourth, the image displays exactly the point he wishes to illustrate: just as this water brought life to lifeless ground even so grace brings life to a lifeless world.
Fifth, the explanation of the metaphor moves the attention to God’s love – which is the overarching point of the sermon. If he had not created movement in the thought by opening up the explanation beyond the precise scope of the metaphor, the result would be to create a jerk and pause in the flow of the idea.
The metaphor itself tied back to the previous illustration which was the search for the source of the Nile. By bringing the explanation of the Texas analogy back to the Nile source analogy, Moody creates a structure which integrates the previous idea – what is the source of grace – with the idea what is the effect of grace?