An American Instagram adventurer and evangelist who was killed by members of an isolated tribe after trespassing on their island left behind a journal detailing his intention to convert the community to Christianity.

John Allen Chau, 26, was shot with an arrow last week on the remote North Sentinel Island in the Bay of Bengal, home to the tiny Sentinelese tribe, which for centuries has rejected all contact with the outside world. The tribe is heavily protected under Indian law, which bans all visits to North Sentinel.

“God Himself was hiding us from the Coast Guard and many patrols,” Chau wrote of his journey to the island in a diary that he left with fishermen who ferried him there. Chau’s mother later passed the pages, along with notes to his family, to The Washington Post.

“Lord, is this island Satan’s last stronghold where none have heard or even had the chance to hear your name?” he wrote in one of the pencilled diary entries.

Chau described his interactions with the tribe on several visits he had made to the island before his fatal trip.

“I hollered, ‘My name is John, I love you and Jesus loves you,’” he wrote, describing some Sentinelese men as being five-foot-five and wearing yellow paste on their faces. Chau tried to speak their language and sign “worship songs” to the tribe, eliciting angry reactions, The Post reports.

Chau claimed that an arrow shot by a teenage member of the tribe had pierced the water-proof bible he was carrying. But a final note he wrote to his family suggests he had resolved to continue despite the risks. “You guys might think I’m crazy in all this but I think it’s worthwhile to declare Jesus to these people,” he wrote in his last note to his family on November 16. “God, I don’t want to die,” he added.

Towards the end of the diary, Chau asked God to forgive “any of the people on this island who try to kill me, and especially if they succeed.”

Local fishermen told police they had seen tribe members dragging Chau’s body along the beach and burying it.

Medical experts have expressed concern that the body could expose the Sentinelese, whose isolation has left them with no immunity to common modern diseases, to potentially deadly pathogens. Indian authorities believe the Sentinelese only number in the dozens.

Seven people have been arrested on suspicion of helping Chau reach the island.