Walmand is a 1984 graduate of Columbia University, where he served as Editor-in-Chief of the Columbia Daily Spectator.

After college, Waldman was a political journalist. In 1986-87, he served as editor of The Washington Monthly. He was the National Editor of U.S. News and World Report, and worked for eight years in Newsweek's Washington bureau as a national correspondent writing cover stories on social issues.

Walmand co-founded Beliefnet in 1999. He was its CEO from 2002—2007, leading it out of bankruptcy to a sale to News Corp.; he continued on as editor-in-chief until November 2009.

In late 2009, he became a Senior Advisor to the Chairman of the Federal Communications Commission, serving out of the Office of Strategic Planning. He was assigned to "lead an open, fact-finding process to craft recommendations to meet the traditional goals of serving the public interest and making sure that all Americans receive the information, educational content, and news they seek." The position arose in response to the report of the Knight Commission on the Information Needs of Communities in a Democracy and other studies that called on the FCC for "new thinking" to "ensure the information opportunities of America’s people and the information vitality of our democracy."

Waldman is also a speaker on topics relating to the spiritual marketplace, the changing roles of religion in America, and the convergence of spirituality and marketing. In 2000, he was named by Time Magazine as an "innovator" in its "100: The Next Wave" feature. He has been a speaker at The World Economic Forum in Davos, Switzerland, "The Resurgence of Religion in Politics" series at The Carnegie Council, The Renaissance Weekend, and numerous religious, policy and media conferences.

Waldman is the author of the New York Times bestselling book, Founding Faith: How Our Founding Fathers Forged a Radical New Approach to Religious Liberty, and is a columnist covering spirituality and politics for The Wall Street Journal Online.

Founding Faith: Providence, Politics, and the Birth of Religious Freedom in America, was published in hardback in March 2008 and in paperback in March 2009 with the revised title Founding Faith: How Our Founding Fathers Forged a Radical New Approach to Religious Liberty. He is the author of an earlier book The Bill, about the passage of the AmeriCorps law, and the book is now often used as a textbook for college courses. Mr. Waldman served as senior advisor to the CEO of the Corporation for National Service, a $750 million government agency that runs AmeriCorps and other volunteer programs.

Waldman has been a guest on CNN, MSNBC, Fox News, ABC News, NPR and has written for Slate, National Review, The Washington Post, The New York Times, the Atlantic and other publications.