Dave Armstrong has a great exegesis of Luke 1:28 here:
socrates58.blogspot.com/2009/04/straightforward-biblical-argument-for.html?m=1
Here’s an excerpt:
"The great Baptist Greek scholar A.T. Robertson exhibits a Protestant perspective, but is objective and fair-minded, in commenting on this verse as follows:
‘“Highly favoured” (kecharitomene). Perfect passive participle of charitoo and means endowed with grace (charis), enriched with grace as in Ephesians. 1:6, . . . The Vulgate gratiae plena is right, if it means “full of grace which thou hast received”; wrong, if it means “full of grace which thou hast to bestow” (Plummer).’ (Robertson, II, 13)
Kecharitomene has to do with God’s grace, as it is derived from the Greek root, charis (literally, ‘grace’). Greek scholar Marvin R. Vincent noted that even Wycliffe and Tyndale (no enthusiastic supporters of the Catholic Church) both rendered kecharitomene in Luke 1:28 as ‘full of grace’ and that the literal meaning was ‘endued with grace’ (Word Studies in the New Testament, Grand Rapids, MI: Eerdmans, 1946, four volumes, from 1887 edition: New York: Charles Scribner’s Sons; Vol. I, 259).
Likewise, well-known Protestant linguist W.E. Vine, defines it as ‘to endue with Divine favour or grace’ (An Expository Dictionary of New Testament Words, Old Tappan, NJ: Fleming H. Revell Co., four volumes-in-one edition, 1940, Vol. II, 171).
All these men (except Wycliffe, who probably would have been, had he lived in the 16th century or after it) are Protestants, and so cannot be accused of Catholic translation bias.
Of course, Catholics agree that Mary has received grace. This is assumed in the doctrine of the Immaculate Conception: it was a grace from God which could not possibly have had anything to do with Mary’s personal merit, since it was granted by God at the moment of her conception, to preserve her from original sin (as appropriate for the one who would bear God Incarnate in her very body)."
