Known for its politics and focus on social justice, Greenbelt was first dreamed up by bricklayer and theologian James Holloway and Christian musician Steve Shaw.
Christian musicians Sir Cliff Richard and Roy Castle appeared on the bill in 1979, but the festival also welcomed artists known to be atheists such as Bob Geldof and Labi Siffre.
Greenbelt said “iconic hip hop trailblazers Arrested Development” had been on their wishlist “for many years”.
“Fronted by artist and campaigning troubadour Speech, the band wear their social conscience and faith firmly on their sleeves,” a spokesperson said.