Barth, Church Dogmatics 1.1, 363:
Quite rightly reference has been made here first and foremost to the New Testament names of Father, Son and Spirit. If these three names are really in their threeness the one name of the one God, then it follows that in this one God there is primarily at least—let us put it cautiously, something like fatherhood and sonship, and therefore something like begetting and being begotten, and then a third thing common to both, which is not a being begotten, nor a proceeding merely from the begetter, but, to put it generally, a bringing forth which originates in concert in both begetter and begotten. But then, applying our ternary of revealer, revelation and being revealed, we can also say quite confidently that there is a source, an authorship, a ground of revelation, a revealer of himself just as distinct from revelation itself as revelation implies absolutely something new in relation to the mystery of the revealer which is set aside in revelation as such. As a second in distinction from the first there is thus revelation itself as the event of making manifest what was previously hidden. And as the result of the first two there is then a third, a being revealed, the reality which is the purpose of the revealer and therefore at the same time the point or goal of the revelation. More briefly, it is only because there is a veiling of God that there can be an unveiling, and only as there is a veiling and unveiling of God that there can be a self-impartation of God.