That's because Yahweh was a sky god and lived high up in the clouds. So raising your hands, standing on mountain tops, etc, reduces your distance to him. Raisin

That's because Yahweh was a sky god and lived high up in the clouds. So raising your hands, standing on mountain tops, etc, reduces your distance to him. Raising your hands while praying doesn't make as much sense anymore since Heaven is a metaphysical concept and not a place in the skies.