Neither I nor Machen are atheists. We both believed God's word that those who are saved by grace through faith in Christ will be glorified at the moment of their death and will sit with Him in heaven forever.
Warmed-over paganism is not pretty. Discard the lies of purgatory for the truth of the Bible. Purgatory does not exists. Jesus made purification for sins on the cross.
"Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high" -- Hebrews 1:3
Again, the RCC teaches error and contradicts the word of God.