[quote="smp501, post:12, topic:286660"]
What's the difference?
Short version: Thomism:
God, by an absolute decree and without regard to any future supernatural merits, predestined from all eternity certain men to the glory of heaven, and then, in consequence of this decree, decided to give them all the graces necessary for its accomplishment. In the order of time, however, the Divine decree is carried out in the reverse order, the predestined receiving first the graces preappointed to them, and lastly the glory of heaven as the reward of their good works. Two qualities, therefore, characterize this theory: first, the absoluteness of the eternal decree, and second, the reversing of the relation of grace and glory in the two different orders of eternal intention (ordo intentionis) and execution in time (ordo executionis). For while grace (and merit), in the order of eternal intention, is nothing else than the result or effect of glory absolutely decreed, yet, in the order of execution, it becomes the reason and partial cause of eternal happiness, as is required by the dogma of the meritoriousness of good works (see MERIT). Again, celestial glory is the thing willed first in the order of eternal intention and then is made the reason or motive for the graces offered, while in the order of execution it must be conceived as the result or effect of supernatural merits.
It is quite obvious that gratia congrua corresponds with efficacious grace, and gratia incongrua with merely sufficient grace. Accordingly the efficacy of a grace depends upon its peculiar agreement or congruity with the interior and exterior disposition of the recipient, whereby a certain relationship of choice is established between grace and free will, which at the hand of God in the light of His scientia media becomes the infallible means of carrying out all His designs of grace in great things and small with certain success and without violence. Even a small grace, which by reason of its congruity is attended with success, has an incomparably greater sanctifying value than an ever so much more powerful grace, which by reason of unfavourable circumstances of inclination, training, and environment fails in its purpose, and therefore as a gratia incongrua appears to the Divine foreknowledge as merely sufficient. Concerning the method of operation of the efficacious, or the congruous grace, the Congruists like the Molinists make three divisions: the efficacy of power (efficacia virtutis); the efficacy of union (efficacia connexionis); the efficacy of infallibility (efficacia infallibilitatis).