What are the main teaching of sikhism

What is the main idea of this excerpt? 1.1.3

Which would make the best heading for this list of notes about the migration of african-americans during the reconstruction era?

Why was galileo galilei brought before the inquisition? for insisting that earth stands still at the center of the universe for proving that planets move in elliptical orbits for putting forth evidence that earth moves around the sun for suggesting that the sun is a star