Moon Knight, Marc Spector, Steven Grant, and Jake Lockley: four different aspects of the same man who was resurrected by Khonshu (the Egyptian Lunar-God of Vengeance and Justice) to serve as his "avatar."
Such is the character Moon Knight, but he didn't start out that way. Originally created as an antagonist for Jack Lockley, the Fist of Khonshu would prove popular with fans and kept getting brought back as a guest star in the 1970s; however, aside from a cool costume, he didn't have much of a personality. Writer Doug Moench saw potential in the characters, and after testing the waters with a trio of stories in Hulk Magazine, he penned what would come to be seen as the Fist of Khonshu's defining comic run in the early 1980s (which remains a fan favorite to this day). Here he established the character's motivations, skills, friends, and even his defining mental problems.
But by the 1990s, Moon Knight's popularity was waning, and it would take a new direction to get him on top again.