There are a lot of challenges in reading 17th-century literature; add to Paradise Regained a basic question as to what exactly is being read. Is this a stand-alone pocket epic or intended follow-up to another epic?
Yes to both is the best answer I can offer. Whether you read it for the history, the religion, or the craft itself, John Milton serves up a challenging, engaging, if unfulfilling treatment of New Testament themes, modelled on how he did the Old Testament in Paradise Lost.