The religious leader who convinced nine hundred followers to kill themselves was Jim Jones.
It was in 1950s that Jim started his Peoples Temple. He was able to establish a lot of churches from then on. He talked about the importance and values of communism in view of Christianity. When his abusive practices were exposed he become panicky and become out of control, he was able to convince a lot of people to commit suicide. And when someone tried to stop them, they ridiculed them.