Samuel Morales had to adopt a 20-point security checklist just to stay alive. Every day, the 40-year-old teacher would take a different route to work, always checking that he wasn't being followed. He'd look for escape routes when entering a room and would never sit with his back to the door.
He has a wife and four children, but could never take them to the cinema or the park for fear of putting their lives at risk. And every six months, the whole family would have to move house.
This is because, as well as being a teacher, Samuel is a trade unionist, as I am. But whereas I have lost only jobs for standing up for my beliefs, he, as regional president of Colombia's United Confederation of Workers (CUT) in Arauca, stands to lose his life.
Despite all his precautions, Samuel was arrested by the Colombian army on 5 August 2004. In the same operation, his fellow trade unionists Héctor Alirio Martínez, Leonel Goyeneche and Jorge Prieto were shot dead, and Raquel Castro was detained.
According to the armed forces, the trade unionists opened fire on the soldiers and were killed in combat. Subsequent investigations have shown that the three dead men were forced out of a house and shot in the back. Despite this, in January last year, Samuel and Raquel, who is also a teacher, were charged with collaborating with the "rebels", and are now sitting in prison awaiting the outcome of their trial.
During his time in jail, Samuel and his family have received death threats. In July last year, while Samuel was in custody in Saravena, the station commander told him he knew where his sisters Matilde, Gladys and Omayra worked, and that he would also be able to find his wife.
In September, the secretary at the school where Gladys and Omayra worked received a telephone call from a man who said he was from the paramilitary United Self-Defence Forces of Colombia (Autodefensas Unidas de Colombia, or AUC).
He told her to tell the sisters they had 72 hours to leave the school, that members of Samuel's family were a military target and that they must disappear from Arauca. The same day, his other sister, Matilde, received a similar death threat.
Colombia is the most dangerous country in the world to be a trade unionist: last year, two trade-union members were killed every week on average. Since 1987, a total of 4,000 have been assassinated or "disappeared".
In a letter from prison, Samuel wrote: "To think, to dissent and to protest is to become a subversive."
Journalists and teachers are high on the list of casualties because their work is to educate and inform. Journalists in Colombia admit to self-censorship simply to protect their lives. As one told me: you have to decide if a story is worth being killed for.
You have to be brave to work under the daily threat of a visit from one of the death squads operating in Colombia - groups such as Death to Trade Unionists, or like the one which sent wreaths to the families of three journalists this year.
What happened to Samuel Morales could have happened to me. It could have happened to any one of us.
Samuel began his career as a trade unionist at the age of 17. In his first post as a primary-school teacher, he and his colleagues created an association for teachers called Asedar, which became affiliated with other organisations in a collective struggle for economic, social and cultural rights.
In 2002, President Uribe's government declared Morales's home department, Arauca, a zone of rehabilitation and consolidation under a nationwide state of emergency, facilitating a crackdown on trade unions and other social groups working with the local population.
As a voice for the rights of workers and the people, Morales has found that his life has become a series of threats and arrests.
Jeremy Dear is general secretary of the National Union of Journalists. To add your voice to the campaign to support Samuel Morales and Raquel Castro, visit: www.amnesty.org.uk/samuel