Five-year-old William proudly told his mom what he learned in school this week. "Hanukah starts on Friday, next comes Christmas, and then, starting Dec. 26, the celebration of Kwanzaa." Not to be outdone, his brother Robert, 3, wanted to show what he and his playmate down the street had figured out all by themselves. "First comes Hanukah," Robert announced, "then the Baby Genius."

My two grandsons, William and Robert, though raised in a Christian home, are looking forward to the holidays -- all of them -- in fact, everybody's. They may be small fry, but they think it's perfectly all right to like people who, perhaps, do things a little differently from them. Robert can't spell "respect," but he practices it.

There are, however, plenty of other people who may be secretly dreading this holiday season. And it's not excessive consumerism or crowded department stores that are putting them off. Listening to three recent visitors to The Post describe the treatment of their holy days, I realized that disquiet over the coming season is based on something worse. Their holy days had been greeted by an ugly kind of in-your-face religious intolerance, practiced, it so happens, by some of the same people who celebrate Christmas.

Consider what Hindus and Jews have already endured this fall with proselytizing by the Southern Baptists, the country's second-largest Christian denomination.

The Southern Baptists' International Mission Board timed the release of a special prayer book to its 40,000 American churches to coincide with Rosh Hashanah, the Jewish New Year, last September. The board's purpose was unambiguous: to evangelize Jews, helping them, in the prayer guide's words, to "be free of the strong influence of materialism," "to make their own lives richer through personal relationships with Christ" and "to come to terms with their own anti-Christian biases." And here's how to win over Jews, according to the prayer guide: "Love them as you would an unsaved relative."

The put-down of Hinduism was even harsher.

A few weeks ago, Hindus' holiest week, Divali, was greeted with a Southern Baptist prayer book aimed at rescuing the "more than 900 million people . . . lost in the hopeless darkness of Hinduism."

To the Southern Baptists, Hindus are little more than "slaves bound by fear and tradition to false gods"; their gods, proxies for Satan, who has a hold on Calcutta; the city, Mumbai, a place "of spiritual darkness."

Southern Baptists plan more of the same for Buddhists, and a prayer guide is in the works for Muslims during Ramadan.

It is that kind of religious arrogance that can make some non-Christians wish the Christmas season would come and go in a flash.

Is it really necessary -- in proclaiming or witnessing to one's own faith -- to delegitimize someone else's, to mock, stigmatize and dehumanize a people because their convictions differ from our own? When that happens, when the faith of others is slandered or depicted as false -- or when the only true believers are regarded as people who see things our way -- doesn't that strike at the heart of what sets this country apart from many others: our tolerance for diverse beliefs, cultures and religions?

The Interfaith Conference of Metropolitan Washington, which brings together the major faiths in the region, takes issue with the Southern Baptists. So do I.

Evangelism has its place. Witnessing and recruiting in behalf of one's faith, as the Interfaith Conference acknowledges, are important in the life of many faith communities. But evangelism does not justify disrespect for the religious convictions of others. Oh, sure, put me under sodium pentothal and I would admit that this would be a better world if everyone saw things my way. But when I open my closed mind, I know the Interfaith Conference has a better take on the matter.

"Though each of us may wish the whole world believed as do we, every religious person must take account of how deeply rooted is the spiritual life of those whose convictions and practices differ from our own," the conference said in a 1996 statement.

So for what it's worth this holiday season, hold fast to what you believe or choose not to believe. But accord others who see things differently the dignity and authenticity you would choose for yourself. That kind of tolerance is the real genius of America.

Maybe that's what little Robert sees coming soon.