The Danish Lutheran philosopher Søren Kierkegaard, widely considered the father of existentialism, expressed (pseudonymously as John Climacus) in Concluding Unscientific Postscript to Philosophical Fragments an approach to God which holds that the Father's hypostasis (existence) has logical primacy over his ousia (essence or substance).
:It must be regarded as certain that the council which condemned Paul rejected the term homoousios; but naturally only in a false sense used by Paul; not, it seems because he meant by it a unity of Hypostasis in the Trinity (so St. Hilary), but because he intended by it a common substance out of which both Father and Son proceeded, or which it divided between them, — so St. Basil and St. Athanasius; but the question is not clear.