As I mentioned before, we often look at the Lord's Supper without considering the most obvious thing: that eating and drinking are the normal path to growth and strength, and that the eating and drinking of the Lord's Supper have this meaning for us spiritually as well. In the same way with baptism, many arguments over its meaning overlook the most obvious thing: it is a washing. The point is not the outward purity of the skin, but the inward purity of the heart and the conscience. As water clears away filth and unhealthy things from the outside, baptism has a similar place for the inside.
Modern Christians often avoid thinking too hard about the physical parts of those acts: the eating and drinking in the Lord's Supper, the washing in baptism.We tend to make our spirituality other-worldly. The bread, the wine, the water -- they are unmistakeably earthly, and without apology. If we avoid those obvious things, we miss the meaning: that God is feeding our souls, or washing us clean. It is one thing if we have gotten the message and then work on understanding better, deeper, more fully. It is another thing if we have missed an obvious point.