Dio was quick to argue that appearances are misleading, that it could just as easily be a priest killing a devil, wanting people not to "judge a book by its cover".

[8] Around the time of making the album, a rise of heroic adventure elements in popular culture (such as J. R. R. Tolkien's The Lord of the Rings books and role-playing games Dungeons & Dragons) were having influence.

"Much of heavy metal took place on similar turf, a realm of dark towers and impenetrable wilderness populated by battles and adversity.

[9] Dio, who had read Sir Walter Scott, Arthurian tales, and science fiction growing up, had previously used fantasy lyrics in his early 1970s band Elf.

"[9] AllMusic reviewer Eduardo Rivadavia praises the album, stating that "aside from Ronnie's unquestionably stellar songwriting, Holy Diver's stunning quality and consistency owed much to his carefully chosen bandmates, including powerhouse drummer and fellow [Black] Sabbath survivor Vinny Appice, veteran bassist Jimmy Bain, and a phenomenal find in young Irish guitarist Vivian Campbell, whose tastefully pyrotechnic leads helped make this the definitive Dio lineup.

"[3] Canadian reviewer Martin Popoff describes the album as "quintessential traditional metal", with Ronnie James Dio "almost single-handedly reinventing gothic hard rock for the '80s, incorporating strong melodic hooks and more than the genre's usual share of velvety, classical-based pyrotechnics.

[15] The rock historian Ian Christe relates that for the post-Sabbath solo career "Dio simplified his stories substantially for a younger heavy metal audience.

In the sharp contrasts of Dio's imagery, there was always a built-in contradiction that fed adolescent revolt: a black side to every white light, and a hidden secret behind every loud proclamation of truth.