The question is not whether sin comes into consideration as a factor in the decree of election and of rejection. On this point much misunderstanding reigns. One frequently hears the claim that those who place election above the fall teach that God has ordained men for eternal bliss and eternal miserly only because he willed to do so and without considering their sin. But that is a conclusion that is not present in supralapsarianism and has never been intended by its advocates.
[Quoting Perkins] insofar as it pertains to the first act, that is, insofar as it refers to the purpose to abandon the creature and in this to demonstrate justice, is absolute…Sin itself occurs after the abandonment and the just permission of God…However, reprobation, insofar as it pertains to the second act, that is the purpose to damn, is not absolute or indefinite but it takes account of sin…God has not created man simply to destroy him, but so that by his just destruction of the sinner he would demonstrate his justice.
The older supralapsarianism [which Vos endorses] at least maintained that in God's decree the permitting of the fall of man together with creation was subordinated to the highest end, the glorification of his justice and mercy.
The supralapsarian taught that in his decree to create God already had in view the elect as his personal beloved.
One will perceive how the question whether in predestination God viewed man as still having to be created and still having to fall (creabilis et labilis), or as created and fallen (creatus et lapsus), is only a short formula for this difference. It would perhaps be better to say creandus [to be created] et lapsurus [to be fallen] for characterizing supralapsarian sentiments…"Will be created" and "will be falling" gives a sense of how sin was certainly taken into account.
The objection that for the supralapsarian the object of predestination is a non-ens (a nonentity) rests on a misunderstanding. It is not a non-ens concerning the knowing part of God's decree but only concerning the willing act. Also, if this reasoning is extended, God could never have made a decree of creation.
One should certainly keep in view that this harshness resides in the doctrine of God's decree as such, and supralapsarianism merely brings it out clearly.
[Quoting Calvin] "God has created us in order to redeem us."
According to infralapsarians, reprobation has two parts: (a) praeteritio, "passing by," God's decree not to grant the grace of salvation to certain persons lying in sin; and (b) praedamnatio, "predamnation," God's decree to commit these persons to eternal destruction because of their sin.
According to supralapsarians, reprobation has three parts: (a) the decree to set apart certain persons for the revelation of God's retributive justice in punishment for their sins; (b) permission in God's decree for the fall of man; (c) the decree not to grant grace to these persons, being once fallen, but to condemn them because of their sin.
The supralapsarian says: The legal ground why men perish lies in sin that they deliberately commit within time. Nobody perishes other than because of his own sin. But this sin itself cannot occur apart from the permission of God's decree. Therefore, this permission, that is, God's predestination, is the highest ground for the reality of perishing, although not the legal ground.
a) That generally hardening is the consequence of contact with the revelation or the truth of God against which sinful men rebels (so, for Pharaoh, Exod 7:3; Isaiah's contemporaries, Isa 6; Mt 13:11-16). "An odor of death to death."
b) That hardening is also caused by God simultaneously withdrawing the common grace of the Holy Spirit and permitting sin to break out and spread unhindered. Here, then, is a real act of God, but it is an act of withdrawing. God does not cause sin to arise in man but withdraws all influences that work for good. This is called, "given over to a depraved mind," 'to dishonorable passions," to the desires of their hearts" (Rom 1:28,26,24; Ps 81:13).
G. Vos, Reformed Dogmatics (Lexam Press 2012-2014)1:144-154