TIM O'BRIEN, guest anchor: A birth, a marriage, a death -- these events are often surrounded by religious ritual and tradition. But how are those passages in life observed by those who do not believe in a God? We went to a baby-naming ceremony sponsored by the Atheist Alliance International. Its president, Margaret Downey, explains:

MARGARET DOWNEY (Secular Officiant and President, Atheist Alliance International): Our ceremonies are based on real things such as love and honesty and commitment and the beauty of nature.

We conduct "Welcome to the World" ceremonies, and they focus on appreciation of the birth of a child. In our case, we had two children to appreciate.

We officially announce their names to friends and family.

UNIDENTIFIED VOICE OF WOMAN: For in Greek Sophia means wisdom, and Lyra refers to music and lyrics.

Ms. DOWNEY: We also give our promises to be mentors and "guideparents." We don't have godparents, so we use the terminology "guideparents."

PARENTS (speaking in unison): We accept this responsibility.

Ms. DOWNEY: Some people bring gifts. Gifts can range from anything from a thought to a scholarship.

UNIDENTIFIED MAN #1: Look to this day, for it is life.

Ms. DOWNEY: Sometimes we do readings. We typically research so that we make sure the poems and the prose do not contain religious jargon.

UNIDENTIFIED MAN #2: They learn justice.

Ms. DOWNEY: We have libraries filled with beautiful works.

RICHARD DAWKINS (Biologist and Author of "The God Delusion," reading): Of all the experiences of our lives, though, surely no event is more inspiring than the birth of a child.

Ms. DOWNEY: Some parents try to find people that serve as good role models for the child. I mean, Richard Dawkins -- what better role model could you have than him?

Today the naming ceremony's theme is "Stardust," and what we did was we put stars around the tables. We put stars on the stage.

We like ceremonies because it reinforces the fact that we have family and friends. It reinforces a date, a time, a marking in someone's life, a special event, and atheists need that, too.