I have written much on the topic of Mariology, including examining, both the biblical and patristic texts, dealing with Mary, as well as discussing why I strongly disagree with the defined dogmatic teachings on Mariology within Roman Catholicism. With respect to the Immaculate Conception, for instance, I have discussed how it is utterly absent in early Christianity, contra Tim Staples et al.:
Indeed, two chapters in my book on Mary discusses the Immaculate Conception, as well as individual chapters on the perpetual virginity, Bodily Assumption, and examples of Marian devotion and apparitions:
Notwithstanding, there are some arguments that are popular against the Immaculate Conception (hereafter, IC), and, as I do believe intellectual integrity is very important, I will discuss why I do not believe that one such popular argument is valid. That is Mary’s offering in Luke 2:21-24:
And after eight days were accomplished, that the child should be circumcised, his name was called Jesus, which was called by the angel, before he was conceived in the womb. And after the days of her purification, according to the law of Moses, were accomplished, they carried him to Jerusalem, to present him to the Lord: As it is written in the law of the Lord: Every male opening the womb shall be called holy to the Lord: And to offer a sacrifice, according as it is written in the law of the Lord, a pair of turtledoves, or two young pigeons. (Douay-Rheims)
The Old Testament basis for this offering is Lev 12:1-8:
And the Lord spoke to Moses, saying: Speak to the children of Israel, and thou shalt say to them: If a woman having received seed shall bear a man child, she shall be unclean seven days, according to the days of the separation of her flowers. And on the eighth day the infant shall be circumcised: But she shall remain three and thirty days in the blood of her purification. She shall touch no holy thing, neither shall she enter into the sanctuary, until the days of her purification be fulfilled. But if she shall bear a maid child, she shall be unclean two weeks, according to the custom of her monthly courses, and she shall remain in the blood of her purification sixty-six days. And when the days of her purification are expired, for a son, or for a daughter, she shall bring to the door of the tabernacle of the testimony, a lamb of a year old for a holocaust, and a young pigeon or a turtle for sin, and shall deliver them to the priest: Who shall offer them before the Lord, and shall pray for her, and so she shall be cleansed from the issue of her blood. This is the law for her that beareth a man child or a maid child. And if her hand find not sufficiency, and she is not able to offer a lamb, she shall take two turtles, or two young pigeons, one for a holocaust, and another for sin: and the priest shall pray for her, and so she shall be cleansed. (DR)
According to critics, Luke is teaching that Mary offered a sacrifice for sin, ergo, she was not personally sinless, ergo, she was not conceived without the stain of original sin, ergo, the IC is a false doctrine. The standard line is: “If Mary had to offer sacrifice for sin, wouldn’t that mean she was a sinner?”
To read one article by Matt Slick, see:
While I strongly disagree with much of his book, I believe Tim Staples offered a rather good response to such arguments in his book on the Marian doctrines. While admitting that “There can be no doubt that Mary offered a 'sin offering' in Luke 2,” he offers, among others, the following reasons why this does not reveal Mary to be guilty of personal sin:
1. The “uncleanness” being spoken of here in Leviticus 12 does not indicate a personal sin has been committed; rather, it speaks of ritual impurity. Leviticus 12:7 says the woman in labor becomes “unclean” because of “the flow of blood,” not because of any personal sin she committed. One must recall that even a woman’s menstrual period would render her “unclean” and in need of “purification” according to the Old Testament (cf. Leviticus 15:19-30). Thus, the fact that the Holy Family made this offering in accord with the law would not mean Mary sinned. She was “unclean” because of the “flow of blood” assumed by the law in the case of childbirth.
2. According to the teachings of Jesus Christ, the “sin offering” spoken of in Leviticus 12 cannot be understood to refer to a personal sin in the one offering the sacrifice . . . Jesus declares that only what comes “out of the heart of man” defiles him, or “gives birth to sin,” as St. James says it (James 1:15). Things that do not defile a man therefore include foods, blood, semen, spit, and other things that were said to “defile a man” in various Old Testament texts (cf. Leviticus 15, 17, etc). These things do not come forth “from the heart.” For there to be personal sin involved, there must be knowing and purposeful disobedience to God’s law. Thus, it follows: Giving birth did not make Mary a sinner.
. . .
5. Along these same lines, Luke 2:22 also references Exodus 13:2 and the Lord’s command to “consecrate to me all the first-born” males. In Exodus 13:13 then says, “Every first-born of man among your sons you shall redeem.” Christ did not need to be “redeemed,” in any sense of the term, yet he was “redeemed” in obedience to the law (Christ was “redeemed” in a ceremonial sense only. He did not need to be redeemed in any sense). (Tim Staples, Behold Your Mother: A Biblical and Historical Defense of the Marian Doctrines [El Cajon, Calif. Catholic Answers, 2014], 119-20, 121-22)
Additionally, with respect to Luke 2:22, as Staples notes (p. 120 n. 164), “Both the King James and the Douay-Rheims versions of Scripture—relying on inferior manuscripts—had it wrong when they rendered this text as ‘her purification.’ The Greek reads as ‘their purification.’” On the importance of the superior reading of Luke 2:22, Staples notes:
Luke 2:22 specified, “When the time came for their purification.” Both Mary and Jesus had to be presented for purification by sacrifices offered for both o them. If one is going to argue that Mary had sin because she had to go through this “purification” rite of Leviticus 12, then Jesus had sin as well. The sacrifice being offered, according to the text, was for both of them. (Ibid., 120)
Luke 2:22 in the NET reads:
Now when the time came for their purification according to the law of Moses, Joseph and Mary brought Jesus up to Jerusalem to present him to the Lord.
Commenting on the textual variation between "her purification" and "their purification," the NET notes the following:
The translation follows most MSS, including early and important ones (א A B L). Some copyists, aware that the purification law applied to women only, produced MSS (76 itpt vg [though the Latin word eius could be either masculine or feminine]) that read "her purification." But the extant evidence for an unambiguous "her" is shut up to one late minuscule (codex 76) and a couple of patristic citations of dubious worth (Pseudo-Athanasius whose date is unknown, and the Catenae in euangelia Lucae et Joannis, edited by J. A. Cramer. The Catenae is a work of collected patristic sayings whose exact source is unknown [thus, it could come from a period covering hundreds of years]). A few other witnesses (D pc lat) read "his purification." The KJV has "her purification," following Beza's Greek text (essentially a revision of Erasmus'). Erasmus did not have it in any of his five editions. Most likely Beza put in the feminine form αὐτῆς (autes) because, recognizing that the eius found in several Latin MSS could be read either as a masculine or a feminine, he made the contextually more satisfying choice of the feminine. Perhaps it crept into one or two late Greek witnesses via this interpretive Latin back-translation. So the evidence for the feminine singular is virtually nonexistent, while the masculine singular αὐτοῦ (autou, "his") was a clear scribal blunder. There can be no doubt that "their purification" is the authentic reading.
On the contention that Luke was in error in his understanding of Lev 12 by ascribing ritual impurity to the new-born child, not just the mother, see Matthew Thiessen, "Luke 2:22, Leviticus 12, and Parturient Impurity," Novum Testamentum 54 (2012) 16-29 which soundly refutes this common argument against Luke’s historical reliability. Indeed, many Jewish texts contemporary with Luke ascribed ritual impurity to the new-born child, consistent with what we find in Luke 2:22. As Thiessen writes (pp. 28, 29), after surveying Jubilees and 4Q265 and its relationship to the offering in Luke 2:
I have argued that Luke 2:22 contradicts neither the legislation of Leviticus 12 nor the childbirth practices of Luke’s contemporary Jews. In fact, one could argue that Luke’s views on childbirth impurity coincide with some of the stricter halakhic rulings on childbirth impurity in Second Temple Judaism . . . Luke goes beyond the written instruction of Leviticus 12, displaying a deeply knowledgeable understanding of impurity, one that comports with the book of Jubilees and 4Q265. Rather, it is later Christian scribes, who demonstrate their book knowledge of Leviticus by conforming Luke 2:22 to the explicit legislation of Leviticus 12. Of course, intimate knowledge of Jewish ritual legislation does not demonstrate that the author of Luke-Acts was a Jew. Nonetheless, perhaps the fact that Luke-Acts evidences sophisticated knowledge of ritual practice should cause us to reconsider long-cherished orthodoxies on the identity of Luke and his portrayal of Judaism and the Jewish Law.
If one wishes to use Mary’s offering in Luke 2 as evidence of her being guilty of personal sin, one must then impute to Jesus personal sin, too, which is heresy (cf. Heb 2:16-18; 4:15). There are much better arguments, biblically and historically, against the dogma of the IC. This particular argument, however, is one that should be retired.