Geyser retired from his professorship in 1983 after 20 years of academic work at the University of the Witwatersrand. He continued his public denouncements of apartheid through a number of writings and interviews despite the high price paid by his family, who were ostracised and physically threatened. Geyser himself survived an assassination attempt when the brakes on his car were reportedly tampered with. In an interview with the Sunday Express in January 1983 he warned that: "A Church in isolation is doomed to futility. It has no function and becomes a museum piece, because the very concept of a Church is that it should be universal". The last 20 years of his life he formally belonged to no church, but attended services in the Anglican, Presbyterian and Nederlands Hervormde (Dutch Congregation) churches.
