Pope Benedict XVI has called on Christians, Muslims and Jews to "root out" religious fundamentalism, on the first day of his trip to Lebanon.
His three-day visit marks the first papal trip to the country in 15 years.
During his stay, the pontiff will meet politicians and leaders from Lebanon's 18 religious groups, many of whom are divided over the conflict in Syria.
The visit coincides with protests erupting across the Middle East and Asia over a film mocking Islam.
"Religious fundamentalism seeks to take power for political ends, at times using violence, over the individual conscience and over religion," the Pope said.
"All religious leaders in the Middle East [should] endeavour, by their example and their teaching, to do everything possible to uproot this threat, which indiscriminately and fatally affects believers."
The pontiff's exhortations were made public as he signed recommendations on how to improve the lives of the Christian minority, making up 40% of Lebanon's population, and its relations with Islam and Judaism.
He also called for an end to the conflict in neighbouring Syria. Lebanon - including its Christian community - is deeply divided over the unrest there.
On his flight to Lebanon, the Pope told reporters that Syrian arms imports were a "grave sin".
Pope Benedict described the Arab Spring as "a desire for more democracy, for more freedom, for more co-operation and for a renewed Arab identity".
He was welcomed at Beirut airport by Lebanon's President Michel Suleiman with a 21-gun salute, and with church bells ringing out around the country.
The Pope told President Suleiman he was visiting the country as a "pilgrim of peace".
He added: "The successful way the Lebanese all live together surely demonstrates to the whole Middle East and to the rest of the world that, within a nation, there can exist co-operation between the various churches and at the same time coexistence and respectful dialogue between Christians and their brethren of other religions."
Correspondents say the Pope is expected to express his concern about the dwindling Christian presence in the Middle East.
The BBC's Jim Muir in Beirut says the pontiff finds a very different Lebanon to the one his predecessor, Pope John Paul II, saw in 1997.
The assassination of Prime Minister Rafik Hariri in 2005 led to the end of Syria's long occupation of the country, an event which was swiftly followed by the 2006 war between Israel and Hezbollah.
Hezbollah - a Shia group - is now the power behind the government but Syria remains the defining issue in Lebanese politics, our correspondent says.
Political parties are divided into pro- and anti-Syrian camps and the violence across the border is increasingly pitting Shia and Sunni Muslims against each other in Lebanon.
In addition to the conflict in Syria, controversy over a film deemed to be offensive to the Prophet Mohammed has raised tensions ahead of the Pope's visit.
As he arrived, hundreds of protesters set alight a Kentucky Fried Chicken restaurant in the northern city of Tripoli.
The film, The Innocence of Muslims, believed to have been made by a Coptic Egyptian Christian in the US, has sparked protests across the Middle East and led to the death of the US ambassador to Libya.