The daughter of an American missionary murdered in the Amazon jungle says she believes God allowed it to happen so the world could see what a real commitment to Christ actually means.
'My father and the other four missionaries definitely knew it was dangerous, but they were willing to give up their lives in order for the Huaorani to know the truth - what we believe be the truth,' Valerie Shepard tells the BBC World Service Witness programme.
Her father Jim Elliot arrived in Ecuador in March 1952 to be a missionary to the indigenous tribes in the Amazon jungle.
He found out about the tribe, then called the Auca tribe, from a pejorative Quechua word for 'savages', through another missionary who had been there.
He was warned they were 'violent, stone age' and knew nothing about the outside world.
Shepherd says: 'It just caught his heart and he felt that those were the people he was supposed to go to.'
He and the missionary pilot Nate Saint took several flights over the Amazonian jungle, looking for the tribe.
He saw an elderly man waving at him from next to a house, and felt he was being invited down.
The five missionaries then flew back, found a beach beside the river, landed and set up camp.
After three days of waiting, two women and one young man from the tribe emerged from the jungle. 'The joy of the five men was that they were perfectly friendly and there didn't seem to be any hostility at all.' But the tribe was suspicious and began to fear they were being deceived. They decided they should kill the visitors before they were themselves killed.
Ten men arrived at the beach, speared the five missionaries and left the bodies in the water.
'After my father's death my mother got to know two Huaorani women who had fled the tribe because of the violence. They said we want you, and the sister of Nate Saint, we want you to come and tell our people about God. While we lived with them, and we were there almost two-and-a-half years, I of course got to know all of the tribe and the ten men who had done the killing.
'Amazingly, I really don't remember being afraid of them. They were always laughing and they would always make my mother laugh. So I simply enjoyed being with them. Of course it was a tragedy and I often wish I had known my dad. Still do. But I really believe that God allowed this to happen so that more and more people could actually see what real commitment to Christ means. And I really don't believe their lives were wasted.'
Besides Saint and Elliot, the other three missionaries who were killed were Ed McCully, Peter Fleming, and Roger Youderian.