For every work [or act] of creation is threefold, an earthly trinity to match the heavenly.
First, [not in time, but merely in order of enumeration] there is the Creative Idea, passionless, timeless, beholding the whole work complete at once, the end in the beginning: and this is the image of the Father.
Second: there is the Creative Energy [or Activity] begotten of that idea, working in time from the beginning to the end, with sweat and passion, being incarnate in the bonds of matter: and this is the image of the Word.
Third: there is the Creative Power, the meaning of the work and its response in the lively soul: and this is the image of the indwelling Spirit.
And these three are one, each equally in itself the whole work, whereof none can exist without other: and this is the image of the Trinity.
From The Mind of the Maker by Dorothy Sayers on page 28 (via Gene Callahan).