First of all... what period? because if you are talking about this time, I think it is becaise they want to feel powerful to be able to have more allied countries in any situation, they also do it because they want to control most of the world natural sources that other countries have.
<span>Anne Hutchinson, born Anne Marbury (1591–1643), was a Puritan spiritual adviser, mother of 15, and an important participant in the Antinomian Controversy that shook the infant Massachusetts Bay Colonyfrom 1636 to 1638.</span>
Information: When it comes down to picking federal judges, you wouldn't want to pick someone you barely know or trust. Would you choose from a place with people you know or place with people you don't know?
Answer: They'd probably choose from their own political party since they are familiar with the people there and know if they are capable or not.
It kept the church from gaining to much power and the govt from gaining too much power it went both ways to cause neutral power between the two.