Great Trek
Cilliers was made the unofficial pastor of the Great Trek, and he would hold services on a daily basis and give Sunday Communion. During the Great Trek he became distinguished as a spiritual leader, earning him such names as "The Prophet of the Great Trek" and "The Father of Dingaansdag (Dingane's Day)". In 1837, he was appointed to one of the two deacons of the first church council elected in the commissioned commandos.