After Christianity, the cult of the emperors marks the most significant development in Roman imperial religion. In fact, scholars today see the two as interrelated: the spread of Christianity is intimately tied to the rise of the Roman ruler cult. To be blunt, at Rome men could be made into gods by law and their worship disseminated to the provinces; naturally, people in the provinces took note. This context highlights the audacity of Paul and other early Christian writers in their calculated attribution to Jesus of the equivalent titles in Greek reserved for the imperial cult.
Matthew M. McGowan, in The University Bookman: Caesar, princeps, Augustus, god.