How do Catholics reconcile the Immaculate Conception with Romans 3:23? How do Catholics reconcile the doctrine of the Immaculate Conception with what it says in Romans 3:23 about all having sinned and falling short of the glory of God?

Romans 3:23 NIV


  for all have sinned and fall short of the glory of God


Thanks!
In essence, the Catholic Church takes the position that Paul is not intending to attribute actual sin to every human being that has ever existed.

For the benefit of readers not familiar with the Catholic doctrine on sin, the Church distinguishes between actual sin (sometimes also called personal sin), which consists in concrete actions in which a person knowingly and deliberately contravenes God’s law, and original sin, which is not “sin” in the strict sense, but the privation of grace that all people (save the singular cases discussed below) suffer before their Baptism. (See Catechism of the Catholic Church [CCC] 405 and 1849.) 

The broader context of 3:23 is as follows:


  But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it—the righteousness of God through faith in Jesus Christ for all who believe. For there is no distinction: for all have sinned and fall short of the glory of God… (Rom. 3:21-23, ESV).


Although it is possible that Paul is referring to passages of the Old Testament (such as Ecclesiastes 7:20, as Marc points out), it is also clear that St. Paul is making the message his own. Nevertheless, in the context of Chapter 3, St. Paul is essentially refuting the idea that the People of Israel have a special advantage with respect to the Gentiles. It is true, argues Paul, that the Jews have the tremendous advantage of the Law and the Prophets, but it has not prevented them from sinning. Rather, he says, “all”—that is, both Jews and Gentiles—“have sinned and fall short of the glory of God.”

It follows that Paul’s use of the qualifier “all” should not be taken to mean “every man, woman, or child that has ever existed,” but rather all human beings in general, and in particular, all human beings including the people of Israel.

Moreover, even just a simple logical analysis of St. Paul’s expression reveals that it cannot be ascribing actual sin to every human being. Clearly, Jesus Christ himself—who is fully man—did not commit any actual sins, and indeed was conceived free of original sin as well. (The union of his human nature to his Divine Nature according to his divine Person makes any kind of sin impossible in him.)

Even among mere creatures, there are many human beings who die without ever committing an actual sin: for example, those who die as young children, and those who have severe mental handicaps.

For all these reasons, it follows that when Paul asserts that “all have sinned” (πάντες γὰρ ἥμαρτον), the “all” (πάντες) is not meant to be applied exhaustively. There is, therefore, no reason that an individual human being could not receive a special grace that preserves him (or her) from original sin and its effects.

(Note that the Church holds that Mary, when she was alive on earth, was always capable of sinning—unlike Jesus Christ—but that she never actually did. Thanks to her preservation from original sin, she enjoyed the ability to avoid committing any actual sins—a possibility that the vast majority of us do not have. See CCC 490-493.)