I throw Holy Water in your direction!
One CANNOT 'keep the moral law'!
By God's grace we do the best we can. But also keep in mind the distinction between mortal and venial sin. Only that latter separates us from God. (I know that you do not accept this distinction but it is an important one.) And if one were to commit a mortal sin, all he would have to do is repent and seek forgiveness in confession. See, a pure gift and not something that I "earn" through works.