The frescos in the Sistine Chapel were the work of some of the 15th century's most respected artists.

The narratives begin at the altar wall and the frescos depict stories from the lives of Moses and Christ. Their goal is to foster a sense of continuity between the Old and New Testaments.

Actually Michelangelo goal was not to show a continuity from the Old and New Testaments though that would be the general consensus from what is depicted in the nine central panels on the ceiling. That is merely an eyeball examination of the those frescos.

I would suggest reading my acadeemically peer-reviewed paper: THE SISTINE CHAPEL: A Study in Celestial Cartography. You can go online and download the pdf file of the paper.