My opinion is that to say this is to have no real idea what the word GRACE means. It comes from the Greek word charis and means: good will, loving-kindness, favor, of merciful kindness.
Yes, the Roman church's definition of grace is VERY different from the unmerited favor given to sinners thru faith, definition we are used to.
There are 2 types of grace in the Catholic system, sanctifying and actual grace. All these graces necessary for salvation were merited by Jesus on the cross and are distributed normally by the church thru the sacraments.
Sanctifying grace to a Roman Catholic is grace that is recieved at baptism and makes the soul pleasing to God. It is analagous to what we would call being regenerated(a new creation in Christ).
It can also be recieved at all the other sacraments to further the purification an sanctification of the soul.
Actual grace is the drawing of the sinner by the Father to repent and be baptized or to repent from mortal sin at confession. Mortal sin destroys sanctifying grace and makes the sinner degenerate or unregenerate again until such time as the actual grace from God draws him back to repentance at the sacrament of confession where he gets sanctifying grace or regeneration.
These graces enable a person to co-operate to achieve or maintain their own salvation.
The works a Catholic must perform to achieve salvation is called a "grace", Eph 2:10, or rather enough grace is "freely" given to them to perform the works. That is why the claim is salvation by grace alone.
I believe these graces are kept by the church in the "treasury of merit", where the graces earned by Jesus, Mary and all the saints over and above what they needed for salvation, are doled out to Catholics by the church.
The works a Catholic must perform to achieve salvation is called a "grace"
-- I never heard of. Grace is grace, love of God to us. The good works we do are first, not done out of obligation and second, they are not grace although they are made possible through grace.