Most people of Selt believe in some form of higher spiritual beings.
Monotheism
The Solar Templars, and the other Monotheistic religions of the world, profess a belief in a single, ultimate divinity, which we translate mainly using the vocabulary of Abrahamic Monotheism.
God is said to be benevolent towards humans and toward life generally, immortal, having always existed, and genderless (but is referred to with male pronouns). In a notable difference with Abrahamic Monotheism, this god is not all-knowing or all-powerful, though he is said to be able to hear all prayers (even those of heathen and heretics) and "none can stand against him," meaning that the lack of omnipotence is more of a theological technicality than a practical limitation; the presence of evil in the world despite the existence of a benevolent and extremely powerful deity is attributed to divine respect for human autonomy, i.e. he does not simply force humans to be righteous, which would rob them of an opportunity to earn their position in the afterlife through their decision to abstain from sin. (Another notable difference with Christianity - the Solar Templars believe that human merit, at least with Divine assistance, is sufficient to attain their eternal reward. This is probably because they do not have a doctrine analogous to the Fall of Man.)
The Solar Temple's scriptures sometimes use the name Aelia poetically for the deity they more usually refer simply as God. Aelia is a feminine name and given female pronouns; higher critics speculate that Aelia was originally a consort goddess who was eventually identified with the supreme divinity.
Ditheism
The Twofold Way, the monolatrous ditheist religion of the Murinal Empire, identifies their Good God with the deity of the Solar Temple, but differs theologically. Notably, they attribute evil to the existence of a second, equally powerful but evil deity, which they do not worship or propitiate. They believe that the actions of the righteous - sinless living and correct ritual conduct - cause the power of the Good God to wax stronger. The Twofold Way believes that its gods hatched from a primordial cosmic egg, in contrast to the Solar Temple, whose God is eternal and without a beginning.
Polytheism
Polytheistic religions believe in multiple gods, some or all of which might be considered legitimate objects of worship. Polytheistic religions of note in the Kingdom of Heghom include Walserane Heathenry and Belvestism.