By Natalia Antelava
BBC News, in Beirut
The march was organised after a Facebook discussion
"Sectarianism kills" and "We are for civil marriage, not civil war" read the colourful banners at Sunday's protest in the centre of Beirut.
Hundreds of young Lebanese gathered to march for secularism in a country that lives under a deeply divisive sectarian system.
Being Lebanese in Lebanon comes second to being a Christian or a Muslim, Shia or Sunni, Orthodox or Catholic.
There are 18 official religious sects and 18 sets of rules, one for each of them.
Because there is no civic code, the law on personal status varies from one community to another. Registration of deaths, births, marriage and inheritance is all handled by religious authorities.
The peculiar result of this arrangement is that different Lebanese end up with different rights.
Muslims, for example, cannot adopt children, Maronite Christians cannot get divorced and it is impossible for many people to marry someone from a different sect.
"This horrible system is ruining our beautiful country. I am here because I want to defend my basic human rights," said Lama, one of the demonstrators.
Lebanon's political system, too, is divided along sectarian lines.
All government institutions have to fill posts according to a sectarian quota, and since gaining independence in 1943 the country's president has always been a Maronite Christian, its prime minister a Sunni Muslim and the speaker of its parliament a Shia Muslim.
'Immense social pressure'
Organisers of the march say that changing the country could be painful
But power-sharing failed to prevent a devastating civil war that began in 1975 and lasted for 15 years.
The Taif Accord, the peace deal which finally ended the fighting in 1990, called for the abolition of sectarianism. But since then politicians have done little, if anything, to bring change.
It was a Facebook discussion that gave birth to the first ever public march against the system.
The movement began a few months ago when a group of young friends angrily discussed a decision by a Muslim cleric to ban a rock concert in Beirut.
"We were talking about how fed up we were with this system. Then someone suggested that we should march for secularism," says Kinda Hassan, one of the organisers.
"We set up a Facebook group and the very next day we had 1,000 members."
The number has been growing since.
Ziad and his wife Reine say they joined the movement because the Lebanese system had failed them.
They come from different religious backgrounds and, since civil marriage is not permitted in Lebanon, they could not get married.
"Our families fought each other in the civil war and then I had a big fight about my relationship. The social and family pressure is immense," Reine says.
Ziad and Reine eventually flew to Cyprus, where they registered their civil marriage. But not everyone in Lebanon can afford an overseas trip and many relationships break up because of the social pressure.
"That's what keeps the society so split, so divided. And it's also unfair. I don't want to be associated with my sect, I want to be Lebanese," says Kinda.
But not everybody in Lebanon thinks that the system should change.
Supporters of this unique arrangement say it gives all religious communities a voice. Without it, Lebanon's fragile and deeply divided society could simply fall apart.
"I feel this system helps me to preserve my tradition, my heritage," says Dima, a young political science student at the American University of Beirut.
"I will never marry anyone outside my sect and I don't think anything will change because there is no way in Lebanon that a Christian from the north, for example, will ever allow his daughter to marry a Shia Muslim from the south," she adds.
Many times over the years, this extremely complex, delicately balanced and fragile society has proved resistant to change.
Organisers of the Beirut March say they know that creating a country where one's religion is no-one's business will be a long and possibly painful process, and that their protest could only be the first step.