Christians can’t “sell” their souls as it is a category mistake in the first place. And even if you could “sell” it, in the sense that you could reject God an

Christians can’t “sell” their souls as it is a category mistake in the first place. And even if you could “sell” it, in the sense that you could reject God and thus one’s own good and choose instead your own self-destruction (hence the irrationality of evil), you could always repent and receive the sacrament of penance. Therefore, no such contract would be binding.