Okay, so lets take Sigmar as a readily available example.
-Sigmar started as a barbarian warlord-smith-hammerguy devotee of Ulric, who was open minded enough to seek blessings from the other gods, tolerant of other races and had the aid of a questionably friendly witch. This guy would have been pretty bewildered by the modern take on Sigmar, especially how the church is fighting with the church of Ulric. He'd have no idea how the fuck you'd even treat a wound beyond asking Shallya or a witch for help. Heck, he'd probably have been just as mystified at the modern Ulricans objection to ranged weapons, they didn't really have much good ranged weapons back then, the modern selection is pretty cool.
-Over the course of his adventures, he united the many tribes into a single Empire, and got them all matched set of runeswords to act as a bond of brotherhood. Given the original era, he probably had his children married with their children to cement the alliance. This was early Sigmar-the-God, God-Emperor of the Empire he made.
-As God of the Empire, his priests needed powers to protect the Empire in battle, so thats what they got. Powers to heal, to smite the greenskin, the beastman, the undead, and the witch. Especially the witch, as all the rest could be handled with thews, but his proto-church were the main option for counterspelling.
-In granting these powers, he changed, his definition shifted. He went from Good Against These Enemies to Hates These Enemies. Thats just cultural drift...but its not like he liked those guys to begin with, so he wouldn't act to tell them "no, this isn't me".
-Then his Church got organized, as they were influential and powerful, and he again shifted. Maybe an earlier Sigmar might have opposed it, but Sigmar God of the Empire of Man isn't the same person, and wouldn't make the same choices as Sigmar God of The Barbarian Federation anymore than Loremaster Mathilde, who uses magic liberally to support her conventional skills, compared to Journeyman Mathilde, who would rather use practical mundane skills and equipment instead of risking miscasts.
And all this...isn't all that different from a person changing as duties and skills are honed.
