It occurs to me that I should clarify one point made in my post on Baptism, found here.
I mentioned that baptism is the normative mode of salvation established by Christ, but that exceptions do occur, since Jesus does save people who through circumstance may be unable to receive baptism.
Since Protestants often use the good thief as a counterexample in order to argue that baptism is NOT necessary to salvation, I pointed to him as an example of an "exception to the rule" that baptism is the normative mode of salvation that Christ established (1).
However, the good thief is not technically a very good example (neither for Catholics as the exception nor for Protestants as the rule), since the Old Law had not officially been replaced by the New Law yet. Thus, technically, circumcision was still how one entered the covenant family of God when the thief spoke those words. Of course, in a few hours/days/weeks (depending on how you look at it), the New Law of Christ would be established, and baptism would replace circumcision as the formal sign of entry into the covenant family of God, the Church.
Our God is a God of mercy. As Fr. John Corapi puts it: "His Name is Mercy!" (Those of you who know his powerful voice can hear him say it!) Thanks be to God for mercifully saving those who profess His name, even on their deathbed or on a hijacked aircraft, who desire (even implicitly) the saving waters of baptism but can not partake of them.
Note:
(1) When it comes to baptism, Protestant apologist often point out the exceptional situations in Scripture in which either 1) a person was saved without baptism or 2) the person received the Holy Spirit before being baptized. Their dogma against the saving effects of baptism prevents them from understanding these situations as exceptional. Certainly, the Holy Spirit can descend upon whomever He wishes, and certainly, no one ever came to a saving faith without the movement of the Holy Spirit already at work in them. None of this, however, provides reason to deny all of the scriptural evidence that "baptism...now saves you." What is needed is a theological perspective that accounts for all the biblical evidence; such a perspective is provided (free-of-charge!) by the Catholic Church. As long as people outside the Church continue reinventing the theological wheel, who knows how many "solutions" to the problematic relationship between the rule and the exceptions people will come up with?