According to the doctrine of the Trinity, the Father, Son, and Spirit are supposed to be distinct from each other, and yet be one and the same God. As if that were not perplexing enough, there is also supposed to be an internal process of production that gives rise to the Son and Spirit: the Son is said to be 'begotten' by the Father, while the Spirit is said to 'proceed' either from the Father and the Son together, or from the Father, but through the Son.
One might wonder, though, just how this sort of divine production is supposed to work. Does the Father, for instance, fashion the Son...