I asked her how she planned to present herself to God, how well she was doing in her program of cooperating with grace. She admitted that her cooperation wasn’t perfect. I asked her what she makes of Galatians 3:10, “Cursed is everyone who does not continue to do everything written in the book of the law” (emphasis added). She admitted that her obedience isn’t perfect but she hoped that her best would be acceptable to God. The late-medieval Franciscans had an expression for this view of grace and justification: “To those who do what lies within them, God denies not grace.” She is relying on what the medievals called “congruent merit,” literally the merit of agreement or covenantal merit. She’s hoping that God will impute perfection to her best effort. (Scott Clark relating a conversation he had with a Roman Catholic woman)
I find this medieval idea to be the nature of common American folk religion--indeed, it may be necessary for all self-propelling religion, since perfection is needed for salvation in most religions. And it's rooted everywhere in the modern sentiment that God won't care about what you believe and do as long as you try your best, as long as you try to be a good person. Hence, since perfection cannot be attained, rather than admitting that salvation is not possible if it is to be accomplished by us, one must resort to this type of thinking---namely, God is so gracious that He'll just reward our good intentions even when we fail to do good and perpetuate evil instead.
But the truth shall set you free, not the "almost-truth" or complete lie with good intentions. And God seems to judge those who may have good intentions but don't obey Him (Lev 10:1-3; 2 Sam 6:6). In other words, God looks at actions as good and evil, not just intentions; and if the whole of the truth and law revealed must be obeyed, then to have good intentions but fail in having good actions is to come under the curse of the law. For God to give salvation where salvation has not been achieved would be to deal out something not only unjust, but also to break His word and to become a liar when He said that such breaking of even one point of the law brings upon one the condemnation of the whole law. Hence, one who does evil or does not accomplish good in one thing becomes guilty of the entirety of the law, regardless of one's intentions and other deeds.
This means that the real gospel is the only true way to be saved. Christ is saved. We must be united with Him in His death and resurrection. We must be His body. He must be our Lord, our Owner. We are told that this unification comes through faith, and that God has had great mercy upon us and has given us grace, due to His great love for us even while we were sinners, so as to bring us to a faith-allegiance with Christ so as to be one with Him and be saved together with Him. He has accomplished the perfection required to be saved. Hence, only those united to Him by faith can be saved with Him. Saying otherwise is like a man who thinks he can deliver himself from death with good intentions. Such is nonsense in the physical world, and so it is also in the spiritual realm.