Please explain how Paul could say Abraham - who lived 430 years BEFORE the Law of Moses - was justified by faith but we, who are here thousands of years AFTER the Law was given, are justified by our works?
Though Catholicism claims that works of the law are different than the good works that justify us, Paul clearly stated that "if a law had been given that could impart life, then righteousness would certainly have come from the Law." (Gal. 3:21) The Law of Moses was the perfect law, but rather than impart eternal life to those that obey it completely (though no one ever could) it was given to point us to Christ, it is our schoolmaster. In fact, those who insist obedience to the law merits our salvation, have set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing! (Gal. 2:21).
We don't earn grace. If we did, it would not BE grace. So whether you say it is the works of the Law or the works of charity that we merit or deserve salvation - it's the same thing - you are setting aside God's grace and going about to establish your own righteousness. You WILL fail.
Of course we do not earn grace through good works. This is not what the Catholic Church teaches. The good works that must accompany faith no more earns us our salvation than faith alone earns us our salvation. Salvation is by grace alone.