Religious faith is very common (most of the region is monotheistic), but actual magic and clerical abilities are nearly non-existent. Magic feeds from life, merely holding a magic item will incur hit point damage.
The more powerful the item, the more it feeds on nearby life. Those within a foot or two of a +1 dagger, might only drain 1 hit point every few days, a +5 dagger might drain 1 hit point an hour, or a +5 keen brilliant energy dagger might drain 1 hit point a minute. Spells, when cast, can have similar effects (think defilers in Dark Sun).
Resources in the region are very, very scarce. Most people are part of hunter-gatherer tribes, but a few have taken the rare "rich" lands available and have me permanent agricultural communities.