The best advice is to ignore what so called Catholic and Protestant scholars think about it...Read and learn what God thinks about it...
Tit 2:11 For the grace of God that bringeth salvation hath appeared to all men,
Tit 2:12 Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world;
Just from those 2 scriptures alone, one can see that grace does not remove sin from anyone...Grace is unmerited favor that teaches us and allows us to chose to live Godly, if we desire...
The word grace used in this passage in Luke is used in one other place in the Bible and that is Ephesians 1 where Paul is us that with this same grace, God has blessed us (believers) in the Beloved. IOW, we all have access to that grace and it has been bestowed on us all.
http://biblehub.com/greek/5487.htm
Luke 1:28 And he came to her and said, “Greetings, O favored one, the Lord is with you!”
Ephesians 1:4-6 In love he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace, with which he has blessed us in the Beloved.
Greek word “grace”
charitoó: to make graceful, endow with grace
Original Word: χαριτόω
Part of Speech: Verb
Transliteration: charitoó
Phonetic Spelling: (khar-ee-to'-o)
Short Definition: I favor, bestow freely on
Definition: I favor, bestow freely on.
HELPS Word-studies
Cognate: 5487 xaritóō (from 5486 /xárisma, "grace," see there) – properly, highly-favored because receptive to God's grace. 5487 (xaritóō) is used twice in the NT (Lk 1:28 and Eph 1:6), both times of God extending Himself to freely bestow grace (favor).
Word Origin: from charis
Definition: to make graceful, endow with grace
NASB Translation: favored (1), freely bestowed (1).
Grace doesn’t remove sin, it is the state we are in when we are free of sin, and can share in the Divine life.