this question is: in a fantasy world (such as Toril) filled with magic and miraculous beings, will the religious concepts of the locals be completely different from those of the human of Earth(which a magicless world)?
In such a world, everything is clear and knowable.
False assumption.
An note on god vs God; many people I know reject capitalization for any but their own god; standard English is God as proper noun, god as common. I'm using the lowercase on purpose.
See, the thing is, with D&D classes...
Only the casters can be certain. A cleric, druid, or paladin is actually in contact with their god. No one else can be certain said cleric is channeling divine magic; most clerical spells before 3E had access to others. Bards have healing magic in 5E... and multiclassing is a thing.
At the end of the day, the afterlife will remain hearsay to at least 99% of people. Sure, everyone knows someone in it, but almost no one can reach them. Those few will want money to make communication... And, depending upon the ruleset in use, there may not be anyone capable outside the biggest cities. 5E isn't as clear on that score, but 3.X has this nifty system of determining highest level of a given class... and resurrection winds up at being available only in really big cities, or by party member casters.
Likewise, the workings of magic are, in a very real way to the inhabitants of Toril, a technology which only works for a few percent of the people... but a technology none the less. Formula X gets effect Y, incredibly reliably. (Games with casting checks aren't as technology-like.) Continual Light or Continual Flame spells are an inexpensive spell, and cities should have enough of them that night is not a threat.