Dates: 1646 · Wikipedia
Summary: The Westminster Confession of Faith (completed 1646 by the Westminster Assembly) settles
the Reformed rejection of purgatory in a single clause of chapter XXXII, "Of the State of Men after Death, and
of the Resurrection of the Dead." Where Rome posited a third post-mortem place where the saved are cleansed by
satisfactory punishment, the Confession recognises only two: at death the righteous are received immediately
into the highest heavens, "made perfect in holiness" at once, and the wicked are cast into hell — and "besides
these two places for souls separated from their bodies, the Scripture acknowledgeth none." There is no purging
interval, no cleansing fire, and so nothing for the living to shorten by prayer for the dead.
Besides these two places for souls separated from their bodies, the Scripture acknowledgeth none.
— Westminster Confession of Faith, XXXII.1, creeds.net. This is the Reformed denial of purgatory in one stroke. By restricting the intermediate state to exactly two destinations, the Confession leaves no room for a third, purgatorial place — and therefore none for the satisfactory cleansing the dead were said to undergo there, nor for the prayers and Masses offered to relieve it.
The souls of the righteous, being then made perfect in holiness, are received into the highest heavens, where they behold the face of God in light and glory, waiting for the full redemption of their bodies; and the souls of the wicked are cast into hell, where they remain in torments and utter darkness, reserved to the judgment of the great day.
— Westminster Confession of Faith, XXXII.1, creeds.net. The phrase "being then made perfect in holiness" is decisive against purgatory: the perfecting of the righteous happens at death itself ("then"), not through a later process of satisfactory suffering. They behold God's face immediately, with nothing left to purge.
The bodies of men, after death, return to dust, and see corruption; but their souls (which neither die nor sleep), having an immortal subsistence, immediately return to God who gave them.
— Westminster Confession of Faith, XXXII.1, creeds.net. The word "immediately" forecloses any delaying state. Against soul-sleep on one side and a purgatorial waiting-and-cleansing on the other, the soul passes to its final destiny the moment the body dies.