Father, Mother and Son are occult terms with standard meaning: father means spirit, the immutable and unreal principle behind reality; mother means undifferentiated matter in its most prototypical form; son is the mix of the two, i.e. the spirit causes that proto-matter to assume meaningful forms, all those atoms, etc. Also, the "Word" is a particular way that process is initiated. The bible has lots of mysterious gems that are difficult to decipher even if you know the terminology, but that's certainly not one of those.