Have to do this in three posts due to length - 1 of 3
The word κεχαριτωμένη is the Perfect Participle Middle/Passive form of the word χαριτόω, a verb which means “to favor” or “bestow freely upon.” It does come from the Greek noun meaning grace (χάρις), however the idea here, as implied by the verb form, is that grace is being bestowed upon or given to the person, not that the person already has it, or is full of it. The only other time that the verb is used in the New Testament is in Ephesians 1:6, when Paul speaks of grace “which He freely bestowed (ἐχαρίτωσεν; Aorist Indicative Active) on us in the Beloved” (NASB). This is why the newer translations render it as “O favored one” rather than “full of grace.” In the interlinear work created by William and Robert Mounce, χαριτόω is defined in the context of Luke 1:28 as “to be visited with free favor, be an object of gracious visitation” (pg. 1194). The NET notes likewise read:
The address, “favored one” (a perfect participle, Grk “Oh one who is favored”) points to Mary as the recipient of God’s grace, not a bestower of it. She is a model saint in this passage, one who willingly receives God’s benefits. The Vulgate rendering “full of grace” suggests something more of Mary as a bestower of grace, but does not make sense here contextually.
Far from the notion that the phrase full of grace “finds its explanation only in the Immaculate Conception of Mary,” let alone that it implies a “godlike state of soul,” even a layman’s study of the angel’s words discovers that, while respectful and signifying the special favor Mary had found with God, it doesn’t represent anything close to what the Immaculate Conception of Mary teaches. In fact, the previously quoted Catholic Encyclopedia even admits that the use of “full of grace” in Luke 1:28 serves “only as an illustration, not as a proof of the dogma” (ibid).
One serious attempt at defending the Roman Catholic understanding of Luke 1:28 can be found in Dave Armstrong’s book The Catholic Verses. In the chapter dealing with this subject, Armstrong writes that “the Catholic argument hinges on the meaning of kecharitomene” (pg. 183). In order to prove the correctness of the Roman position, he takes the noun form of the word (χάρις), cites several passages from the epistles of Paul and John that speak of salvific grace, and then argues that, as Mary was said to have been “full of grace,” this clearly meant she was, in essence, full of salvific grace and hence completely saved and sinless (pg. 183-184).