 Second, in the Trinity, each part is co-equal with the others. In theory, the same is true in the three branches. Third, someone said the Trinity gives Christian belief stability, and the three branches have led to a stable United States for over 200 years. But there are many things that come in threes. The three branches could be modeled upon. Three legs of a stool, for example. But the U.S. government is not based on the design of a stool either.