This is for mathematics. However I found this - Gödel was a convinced theist. He rejected the notion that God was impersonal. He believed firmly in an afterlife, stating: “I am convinced of the afterlife, independent of theology. If the world is rationally constructed, there must be an afterlife."[16] He said about Islam: “I like Islam: it is a consistent [or consequential] idea of religion and open-minded."[17]
You see geniuses can be believers in God, let alone Islam.
There are all sorts of non-math things that cannot be proven true or false.
Whether we are in a simulation or not.
Whether memory is to some degree accurate.
Whether there are other minds or not. IOW solipsism.