Use the Embryo Theory to Promote Understanding: Think of the function and responsibilities of human beings in the whole universe as being similar to that of blood in a human embryo. Part of the blood provides nourishment so individual cells can function and grow. Part of the blood cleans away by-products. Part of the blood protects against disease, etc.
See Building the Body of Christ for more detail.
Salt & Light Matthew 5:13-16.
Lord's Supper: Matthew 26:17-30 -- body 26, blood 27; Mark 14:12-26 -- body 22, blood 24.