In 1957, while a student at the Liceo Celedón, civic strikes broke out throughout Colombia to protest the dictatorship of Gustavo Rojas Pinilla.

He became political secretary of the National Secretariat of the Young Communists and participated in 1963 as a delegate for the organization in the 16th Komsomol Congress in Moscow where he received a course in social sciences and criticized the dogmatic study that characterized the school of squares.

He became the personal secretary of Manuel Marulanda Vélez, Jacobo Arenas and Ciro Trujillo performing political duties for the Revolutionary Armed Forces of Colombia (FARC) until he left in 1970.

After coming to these beliefs Bateman developed an urban political and military movement in 1970 along with Carlos Toledo Plata, the main leader of the Socialist ANAPO.

After the dubious elections of April 19, 1970, in which conservative candidate Misael Pastrana Borrero won over the ANAPO candidate and former dictator Gustavo Rojas Pinilla, Bateman launched the 19th of April Movement with the banner: "With the arms, with the people, with María Eugenia Rojas to the power", however the Directorate of the ANAPO denied such support for armed groups.

Then Senator Germán Bula Hoyos and who proposed the law to give amnesty to political prisoners was the first government official to meet him in person.