In the comments on my post "Baptism for the Dead: It's Not for Catholics Anymore," a reader writes:

Does the Catholic Church recognize other chuches' baptisms as valid and saving ordinances? What about method of baptism--i.e., sprinkling, immersion?

I know that they don't accept LDS baptism but I am interested to know about other churches that have "valid" baptism in the eyes of the Catholic Church.

When the reader refers to "LDS baptism," he means a baptism performed by the Church of Jesus Christ of Latter-day Saints, commonly known as the Mormon church. Ordinances is a Mormon term for religious rites that must be performed in order to achieve salvation.

To put the question in Catholic terms, what conditions must be met in order for a Christian baptism to be considered valid?

The Sacrament of Baptism has two essential elements: the pouring of water over the head of the person to be baptized (or the immersion of the person in water); and the words "I baptize you in the name of the Father, and of the Son, and of the Holy Spirit." Thus, to answer the reader's second question first, immersion--the form in which Christ Himself was baptized--is acceptable, though Catholic baptism (and most mainline Protestant baptisms) are normal performed through pouring or sprinkling of water.

In addition to the two essential elements, however, the person performing the baptism must intend what the Catholic Church intends in order for the baptism to be valid. In other words, when he baptizes "in the name of the Father, and of the Son, and of the Holy Spirit," he must mean in the name of the Trinity (not of three separate deities, as the Mormons do), and he must intend to bring the person being baptized into the fullness of the Church.

Since Eastern Orthodox and Protestant denominations meet the two essential elements as well as have the proper intention, their baptisms are considered valid by the Catholic Church.

You can find out more about "the door of the Church" in my article on The Sacrament of Baptism.

If you have a question that you would like to have featured in our Friday "Reader Questions" series, send me an e-mail at catholicism.guide@about.com. Be sure to put "QUESTION" in the subject line, and please note whether you'd like me to address it privately or on the Catholicism blog.