The whole world, it seems, is moving heaven and earth to find Christina Williams.

In the 3 1/2 weeks since Christina, 13, was last seen walking her dog near her family's home at Fort Ord, Calif., the picture of her pretty face - her dark hair, easy smile and bright, trusting eyes - has been fixed in our collective memory by countless fliers and news reports, seen everywhere from local street corners to national TV.As it often happens when a child is stolen, we as a people, a caring community, have become united, focused in our effort to find her.

Remarkably, for the moment, we have set aside our usual differences to stand behind Christina's family and the men and women in law enforcement, to get her back and bring her abductors to justice.

There is little that we all ever seem to agree on. Yet on this, we are clearly of one mind: She is our child. She belongs to all of us. We want her home, where she belongs.

It was that same resolve, that single-mindedness of a community, that I saw five years ago when I was sent to Petaluma to report on the kidnapping of Polly Klaas.

Polly, 12, had been taken from her home by a man with a knife during a slumber party as her mother slept close by.

Petaluma, a small town with more cows than stop signs, was said to be a "safe" place, a great place to raise a family, the kind of place where bad things weren't supposed to happen to children - much like the Monterey Peninsula, or anywhere called "home."

There, much the way it has happened here, the community was outraged, awakened like the proverbial giant into a force to be reckoned with.

Housewives, bankers, young children, old people, they all did what they could - searched fields and handed out fliers, answered phones and fed volunteers, kept the pressure on investigators to pursue the case and found ways to keep the media interested.

For two months, they kept searching, praying, clinging to hope - knowing without it, Polly might never be found.

On a cold, December night, I stood in the search center with a roomful of volunteers and watched them fall to their knees, devastated by the news that Richard Allen Davis had led police to Polly's body.

Many of those people never knew Polly Klaas, never heard of her until she was abducted. But having been with them that night, I can bear witness to their anguish. I've no doubt, none at all, that she was their child. And that they did their best to bring her home.

Much is said about all the madness in the world, the minefield of horrors where we send our children out to play.

We don't dare discount the power and magnitude of evil. But we owe it to our children to tell them the whole truth - that when evil shows its face, an army of good people will rise up to beat it down.

We need to make them aware, but not wary, of danger; to teach them that a few people can't be trusted, but most want to be their friend; to assure them that, no matter how it may seem, stranger abductions are rare.

They should see how hard we are searching and praying for Christina. They need to know that for any child - even one we've never met - we will surely move heaven and earth.