McMurphy’s self-sacrifice for the benefit of the other patients begins to surface after he defends George, and also when he undergoes the electroshock treatments. McMurphy is belted to a cross-shaped table, an obvious allusion to a crucifix. This Christ imagery suggests an impending martyrdom on the part of McMurphy, and he even compares himself to Christ when he asks whether he gets to wear a crown of thorns. Of course, a martyr ultimately must sacrifice himself to save others. This proves true, since although Bromden feels strong enough to withstand the effects of the electroshock, McMurphy weakens under the repeated treatments. Bromden finally begins to feel that his victory over the hospital is complete. He is no longer ruled by his fears or his past, thanks to the help of his unlikely savior, McMurphy.
After Nurse Ratched provokes Billy, leading to his suicide, McMurphy truly does become a Christ figure for the patients. Under the invisible but heavy pressure of the other patients’ expectations, McMurphy makes the ultimate sacrifice to ensure that Ratched cannot use Billy’s death to undo everything they have gained. By attacking Ratched and ripping her uniform, he permanently breaks her power but also forfeits his own life. Though Ratched tries to give McMurphy a fate worse than death by having him lobotomized, Bromden dignifies McMurphy by killing him, assuring that McMurphy will always be a symbol of resistance instead of a lingering cautionary tale for future patients on Ratched’s ward.