(CNN) – The details of the attack on the World Trade Center and the Pentagon, and the plane crash in a field in Shanksville, Pennsylvania, will be remembered at length this week. What, when, how and who will dominate the headlines. As people across the country head to churches, temples and mosques this weekend, they will once again wonder why. They will look to the pulpit and listen for an answer.

This week, clergy of all faiths are preparing answers as their congregants ask why 9/11 happened, how it should be remembered and what their response should be as they go out from their sacred space and back into the secular.

For some, there will be calls to patriotism among the prayers. Others will shy away from country.

The remembrances cover a wide variety. Some churches will bring care packages to first responders, Dodger Stadium in Los Angeles will be packed for a prayer service Saturday, and there will be hundreds of churches simulcasting services featuring megachurch pastor Rick Warren or other famed clergy.

We spoke with clergy of many different faiths, in many different parts of the country, and asked how they were preparing and what they would tell the faithful as the 10th anniversary of 9/11 falls on a Sunday.

The Rev. Rich Smith had just arrived as the pastor of a church in Bethesda, Maryland, just outside Washington, D.C., in 2001. His first Sunday was September 9, 2001. On the morning of the 11th, they were planning for the next service. "A lot of that had to go out the window," he said.

He was fortunate, he said, because no one from the church died in the attack. A family joined later and the husband, a lieutenant colonel in the Army, was at the Pentagon when the plane struck on 9/11. "He described running as the floor was collapsing behind him," Smith said.

Smith said that 9/11 "affected the whole nine years I was there."

Today, Smith pastors the First Congregational Church in Reno, Nevada, part of the United Church of Christ.

"Even though Reno wasn't attacked, I think people feel like we as a nation were attacked. Even when you're out in the hinterlands like we are, you still feel like you're part of something bigger."

For their 9/11 services, thousands of Catholic and Protestant churches that follow the lectionary, a standardized collection of scripture readings, will be reading from the Gospel of Matthew, where Jesus teaches his disciples how to forgive.

Smith's church will do the same. He said there's some providence to the timing of the passage.

As he preaches about forgiveness, he will remind his congregants of a quote from Nelson Mandela. South Africa, he said, was a, "marvelous example of how you handle something when you feel like you've been so wronged."

"I love the phrase Mandela used, 'No future without forgiveness.' "

In New Orleans, Catholics sitting in the well-worn pews of St. Louis Cathedral in the French Quarter will hear the same passage from Matthew and a similar theme from the Rev. Msgr. Crosby W. Kern when he steps up to the pulpit.

"Forgiveness is probably God’s plan. We don’t forget. We don’t let our guard down. We as a people should be defensive to protect ourselves. But have we got that same sense of mercy and forgiveness we see in God the Father? Whatever our attitude is to our enemies, it’s a good time for us to reflect one that," Kern said.

He will preach to a group of congregants who faced different struggles in the past decade. The statue of Jesus in the back of the church is still missing fingers, a scar from Hurricane Katrina; one that Kern hopes to restore this year.

"We don't forget. We learn. But part of the American psyche is, we are big enough to forgive. We are big enough to try and get over the scars and the wounds that we've suffered throughout our history. It might take a long time, but we can't give up," he said.

In the passage in Matthew, Jesus tells Peter he should forgive the person who has wronged him seven times seventy. "In scripture for us, that's eternal. That's the perfect number, without end. So I'm going to take off on the forgiveness part," explained Father Adam Lee Ortega y Ortiz, Pastor of Santa Maria de la Paz Catholic Church in Sante Fe, New Mexico.

"I know people are meditating on the evil of the attack and the anger it brought about," he said. "When we can quench the anger in our own hearts first, we can do a lot better in the world."

Chaplain Capt. Mijikai Mason, a Southern Baptist minister, will be preaching Sunday to a group of high school students at a military academy outside Columbia, South Carolina. As a member of the Army, he has lived the response to 9/11 and the wars that followed. His audience this Sunday were toddlers at the time of the attack.

He will preach on theme of remembrance. "Now we’re in more of a healing phase. Now it’s more how will we remember and celebrating the lives that were lost,” he said.

Maj. Tommie Pickens, one of Mason's fellow chaplains, is being flown to Chicago to deliver the message Sunday at Addison Community Church on the west side. Pickens said the church is patriotic and loves the U.S. and its military.

He will be preaching from 2 Chronicles 7:14: "If my people which I call by name, humble themselves and turn from their wicked ways, then will I hear from heaven and heal their land."

The verse refers specifically to ancient Israelites but has been interpreted throughout the ages to apply to any country at any time and is very popular with American evangelicals.

Pickens will preach about the first responders, the troops and the spirit of unity that swept the country after the attack, "and lifted the simple prayer, 'God bless America.' "

"We need to remember the cost of the human lives," he said. As congregants go out after the service, he wants them to remember to "be proud of our great nation. Be proud we live in the land of the free because of the brave. Our nation has always exemplified resolve."

"We can stand tall even at the end of a horrible day," he will emphasize.

Days after the attacks, the Rev Billy Graham stood and delivered a sermon to the nation at Washington National Cathedral. Ten years later, Graham is 93 and does not have the stamina to participate in any services, said his daughter Anne Graham Lotz.

His health is failing, and his daughter will be taking the pulpit this year.

Her message will focus on Isaiah Chapter 6, which pertains to when Israel was in crisis and how the prophet's life was shaken.

"When his life was shaken, he didn't say, 'why me?' and allow his life to be filled with self-pity. He looked up," she said.

"I'm going to take that and flesh it out," Graham said. "I think it's very appropriate that in times like this, we look up and ask God to give us a fresh glimpse of himself and a revelation of truth." Her sermon will be in Raleigh, North Carolina, and simulcast around the world on radio and TV.

Tony Campolo will be guest pastor at Trinity United Methodist Church in Little Rock, Arkansas. Campolo is a professor of sociology at Eastern University, a Baptist school not far from Philadelphia. For years, he has been a popular speaker and author, and he relishes his role as the guy who comes in to speak and gets to leave at the end of the service. It frees him to speak what he feels God is calling him to say.

"If I anger people, I'm gone. It's easier for me to sound the prophetic voice than someone who is there all the time," he said.

Campolo will also be preaching on Isaiah Chapter 6 but will take a different approach than Graham.

"The focus of the passage is that there is a sense that in a national crisis, each of us is called upon to stand up and be instruments of God for making things right in the world," he said.

He will also warn congregants against the radical elements in their own midst, not just in other faiths. "All religions have the tendency to create extremism, and in the words of Fredrich Nietzsche, 'Men never do evil with more enthusiasm, than when they do it in the name of God.' And we must recognize that the evil we see in the extremists in the Muslim community that brought about 9/11, is the extremism that we can find in the Jewish community and in the Christian community."

"Revenge is not the way of God's people," he will say, knowing that the memory of 9/11 can stir up old emotions and broad hatred that he says is "unbefitting of religious people."

Rabbi Shmuel Herzfeld of Ohev Sholom - The National Synagogue in Washington, D.C., said that though terrorists misused the name of God to commit their atrocities, in many ways, 9/11 brought Jews and Muslims closer.

He will use his time in the pulpit to warn against cynicism the attacks may have allowed to creep in. "Al Qaeda punctured our belief in ourselves, and we need to remember to ignore them. Al Qaeda’s greatest threat is not the physical, but the attack on our belief in our own destiny; they have spread disbelief and cynicism throughout our land," he plans to say.

"This 9/11, let us remember the dead. But let us also remember the great things we have accomplished in our history and promise ourselves that despite the evil intentions of al Qaeda, we will continue to soar for greatness."

Charles Park is pastor of the nondenominational River Church in Manhattan. They are partnering for a joint service with the Lower Manhattan Church, which was founded after the attacks by Rick Warren's Saddleback Church as a way to minister to the community nearest to ground zero.

Both churches meet blocks from ground zero, and on Sunday, Park will speak to congregants who watched what happened 10 years ago in person; congregants who brushed the toxic dust of falling buildings off their jackets and had to move on with their daily lives.

"I will be focusing on 'how to move forward from 9/11' because as one wise person said, 'Every pain that is not transformed is transmitted,'" Park said in an e-mail.

He will lean heavily on the prayer of St. Francis, "to remind the people of faith the calling from God to be a 'blessing to all peoples on Earth.' "

"Lord, make me an instrument of your peace."