Al Jazeera has gained exclusive access to Latin America's longest lasting guerrilla army, the Revolutionary Armed Forces of Colombia, or FARC.

Colombian authorities accuse the FARC of supporting the international drugs trade, but fighters on the ground say they are bringing social services to Colombians in rural jungle and mountainous regions of the long conflicted country.

A FARC surgeon who asked to be identified as Yesid, told Al Jazeera, "What we try to do each day is to win over the masses, because the side that wins the support of the masses wins the war."

But the FARC is facing major challenges, as Colombia's top military commander said last month that the group was in its death throes.

Only tests of time will tell, but after 50 years of leftist warfare, some FARC members remain confident that they are on the right side of history.

Karl Penhaul reports for Al Jazeera from the jungles of Colombia in part two of our exclusive series.