What was the role of the church in everyday life during the middle ages?

Which fact would this be, and how might you verify the truth?

Who was saul? explain his relationship to david and the importance of david to both christians and jews.

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.