After four years of negotiations, the Colombian government and the FARC rebels officially agreed to a peace deal Monday, bringing the end to the 50-year conflict within sight. The agreement will bring the rebel group into the political process, in return for the cessation of guerilla violence that has killed some 220,000 people and displaced millions more in Latin America’s longest running conflict.

The signing ceremony is a big step towards ending hostilities that have waned in recent years, but still simmer in certain parts of the country. There are political hurdles that remain before the pact becomes law. The peace deal now will go before the Colombian people for a vote in a referendum scheduled for October 2. The FARC rebels have voted unanimously in favor of the agreement. Colombian President Juan Manuel Santos has backed the political compromise that includes amnesty provisions for former-fighters as part of a transitional justice regime, but there are many in Colombia who see the settlement as far too lenient in its handling of the Marxist guerilla group that terrorized the country for decades.

Polls taken in recent months show that the Colombian people signing off on the deal is no a sure thing. “No one should doubt that we are moving into politics without arms,” FARC leader Timoleon Jimenez said during the signing ceremony. “Let us all be prepared to disarm our hearts.”