earlier implicit Christianity and embraced an ahistorical form of polytheism instead.
For that reason, there were growing cries among some gamers to "fix" the cleric. In this context "fix" means change to make it less tied to a particular religion, in this case a particular religion the game itself had eschewed. The first time I recall seeing an "official" answer to these cries was in Deities & Demigods, where it's noted that the clerics of certain deities had different armor and/or weapon restrictions than "standard" clerics. A few even got special abilities reflective of their divine patron. This idea was later expanded upon by Gary Gygax himself in his "Deities & Demigods of The World of Greyhawk" series of articles, which I credit with giving widespread attention to this idea. I know that, after those articles appeared, lots of my fellow gamers wanted to follow Gary's lead and tailor their cleric characters to the deities they served, an idea that AD&D more formally adopted with 2e in 1989.
In issue #85 (May 1984) of Dragon, Roger E. Moore wrote an article entitled "Special Skills, Special Thrills" that also addressed this topic. Moore specifically cites Gary's articles as his inspiration and sets about providing unique abilities for clerics of several major pantheons. These pantheons are Egyptian, Elven, Norse, Ogrish, and Orcish -- a rather strange mix! Of course, Moore intends these to be used only as examples to inspire individual referees. Likewise, he leaves open the question of just how to balance these additional abilities with a cleric's default ones. He notes that Gygax assessed a 5-15% XP penalty to such clerics, but does not wholeheartedly endorse that method himself, suggesting that other more roleplaying-oriented solutions (ritual demands, quests, etc.) might work just as well.
Like a lot of gamers at the time, I was very enamored of the idea of granting unique abilities to clerics based on their patron deity. Nowadays, I'm not so keen on the idea, in part because I think the desire for such only underlines the "odd man out" quality of the cleric class. Moreover, nearly every example of a "specialty cleric" (or priest, as D&D II called them) still retains too much of the baseline cleric to be coherent. Why, for example, would a god of war be able to turn the undead? Why should almost any cleric wear heavy armor and be the second-best combatant of all the classes? The cleric class, even with tweaks, is so tied to a medieval Christian society and worldview that it seems bizarre to me to use it as the basis for a "generic" priest class. Far better, I think, would be to have individual classes for priests of each religion or, in keeping with swords-and-sorcery, jettison the class entirely.