AS President Obama prepares to deliver his second Inaugural Address, beware: second inaugurals have not fared well in American history. First inaugurals have provided many memorable lines. Franklin D. Roosevelt, taking office in the riptide of the nation’s greatest depression, asserted, “The only thing we have to fear is fear itself.” John F. Kennedy told Americans, “Ask not what your country can do for you — ask what you can do for your country.” By contrast, the words of second inaugurals have largely slipped from memory.

Why have second inaugurals fared poorly, and why did Lincoln’s succeed?

To begin with, second inaugural addresses are almost always too long. Jefferson, Madison, Monroe, Jackson, Grant, Reagan, Clinton and Bush II all gave second addresses longer than their first. Lincoln understood that less is more. He spoke only 701 words.

Second, one word typically dominates second inaugural addresses — “I,” “I” and “I”! Re-elected presidents like to personalize second inaugurals — believing they have more of a mandate than they did the first time around.

By contrast, Lincoln disappeared in his second inaugural. The speech contains the word “I” only once. Lincoln was pointing beyond himself to the future of the American democratic experiment, “to do all which may achieve and cherish a just, and a lasting peace, among ourselves; and with all nations.”

Third, second inaugural addresses are often too predictable. Audiences come expecting to hear about second-term agendas. Lincoln’s audience expected him to answer key questions. Would the Confederate States of America be treated as a conquered nation? How should one distinguish the guilty from the innocent?

But maybe it’s a bad idea to give an audience too much satisfaction. Lincoln decided not to address any of these questions. If his listeners expected a triumphalist address heralding a victorious North, they were instead asked to help initiate a new era of reconciliation — one marked “with malice toward none, with charity toward all.”

LINCOLN also surprised his audience by steeping his address in religious language. In those 701 words he mentioned God 14 times, referenced the Bible 4 times and emphasized the importance of prayer 3 times. The point is not to count but to listen to the way he invoked religion as a balm for a nation deeply divided.

Lincoln, so knowledgeable of the Constitution, understood that even though the founders separated church and state, America has never separated religion and politics. Lincoln is instructive in how religion can become inclusive. “Both read the same Bible, and pray to the same God,” he said, telling an audience angry at the deaths of so many sons that the South read the Bible as much as the North.

Lincoln made a final move that also set himself apart. Inaugural addresses can be exercises in self-congratulation, both of the candidate and the nation. In his second Inaugural Address Lincoln, quoting Matthew 18:7, lovingly scolded America. “Woe unto the world because of offenses,” he said. Lincoln dared to declare there was something evil at the core of this great nation: “If we shall suppose that American Slavery is one of those offenses.”

This year’s audience will expect Mr. Obama to detail his priorities for the next four years, from fixing the economy to reforming immigration to curbing gun violence.

Maybe, like Lincoln, he should surprise his audience.

At the service in Newtown, Conn., we heard a president sure-footed in invoking faith as an antidote and using Scripture not as a mere illustration but as the core of his argument. Many have wondered why this side of the president remained veiled during his first four years. This summer, one of the president’s spiritual advisers told me that the president did not want to politicize religion. I respect that answer. But his fellow citizens would welcome the spirit of the man we heard in Connecticut, who called for deep healing, not only for the grieving parents, but also for a hurting nation.

Daniel Day-Lewis’s riveting portrayal of our 16th president in the movie “Lincoln” has meant that our most eloquent president has emerged once again in our national dialogue. No president has come into office with a surer grasp of Lincoln than Barack Obama. He knows Lincoln continually surprised those closest to him. What the nation needs on Jan. 21 is not a lawyerly, rational address on the issues facing our nation but a president ready to share his heart. And daring to tell us how we must change.