Why did Nate Saint go to Ecuador?

In 1956, five missionaries attempted to make contact with a tribal group, in the jungles of Ecuador, known as the Aucas. To be correct, their real name was Waorani but they were known as Aucas to the outside world. The initial contact was positive but, when the five went back for another visit they were killed.

One of them was Nate Saint, a pilot, who had a son, Steve. Steve Saint was almost 5 when his dad was martyred for the cause of Gospel. Many years later he gave an interview in which he said the following : 

"People ask me why my parents went to Ecuador and the answer I give is simple. When I was at college I was in my room, one day, and could smell smoke, when I opened the door and looked out I could see there was a fire. Being on the 3rd floor this was a highly dangerous situation. However, by crawling along the floor I managed to escape only to find that a group from my floor had already left the building and were gathered together outside. It transpired that they had gone right passed my door but hadn't bothered to knock and warn me. If they had warned me it would have been my responsibility to make a choice to leave the burning building or to stay. However, it was their responsibility to warn me. In a similar way we have a responsibility to give people a chance to be saved by spreading the Gospel". 

When I heard that I was reminded of Ezekiel 33 and the watchman. In verses 1 to 9 we are told about the watchman's responsibility to sound the alarm and it makes sobering reading for all of us, as Christians.