One thing you should understand is that "God" does not mean the same way in other culture. Kim Il Sung is probably not seen as Christians/Jews/Muslims view their "God". In essence, they are not really supernatural in the sense that they have omnipotent powers, but are chosen by the sky/nature. Kim Il Sung is probably seen as someone sent from heaven in a way that present him as the "Promised Leader" much like the mandate of heaven. Kim dynasty surrounds themselves with myths regarding their birth or certain events. For example, Kim Jong Il is said to have been born on Mt. Baektu, the tallest mountain in Korea and a place of spiritual, cultural and historical significance. These kinds of "Stars aligning" events gives sort of credence to their claim as rulers of North Korea as being mandated by the sky or nature, and their being leaders is clearly a natural and obvious thing. These myth tries to parallel the Kim dynasty to founding fathers of essentially all the kingdoms of Korea. In that sense, many people probably believe that they were chosen by the sky since it doesnt particularly contradict with whatever outside cultural information or material they are able to get their hands on.