This is part 1 of former Fairfax Media Indonesia correspondent Michael Bachelard's series on Papua. Here is the introduction to the series is here

On a chilly Sunday evening in Wamena, the highlands capital of Indonesian Papua, a small group of white Christian missionaries worship together in an open-sided shed.

They talk about their projects – bible translations and Christian outreach – and pray together as their children chase each other around the concrete floor. When it's over, as a cold rain starts to fall, a Dutch couple board their bicycles – a blonde-headed child strapped on the back of each – and ride home, dodging muddy potholes in the darkening streets.

Sue Trenear, long-serving Christian missionary at her house in highlands Wamena. (November 2014/Michael Bachelard.)

These missionaries are the spiritual descendants of hardy men and women who converted the Melanesian tribes of the Papuan highlands to Christianity through the 20th century. Up until the late 1960s they braved cannibalism, and a number fell victim to it.

The surprise is that, in 2015, they are still here and still at work.

Mission Aviation Fellowship (MAF), a modern day incarnation of the original missionaries, has a small fleet of planes which are the only practical way (besides walking) to access hundreds of remote villages. Airstrips have been hacked by hand into hillsides, and seats on MAF flights are in high demand. You might find yourself sharing a flight with a live pig or two.

Aid workers, academics, journalists and NGOs are treated with suspicion by Indonesian authorities as they apply for work visas – it's feared they may be agents of 'foreign interference'. But missionaries seeking religious visas find the process significantly simpler. Many Papuans still view with rosy nostalgia the time when missionaries were the live-in spiritual guides and providers of health and education services in many villages.

Sue Trenear is their grand dame. An Irishwoman who trained in Scotland, she arrived from Glasgow in 1978 and stayed. Indonesia declared its power over the Central Highlands in 1977, the year before Trenear arrived, by killing perhaps 4000 people, strafing villages from helicopter gunships and, according to a recent human rights report, burning and boiling people alive. It will never be forgotten.

Trenear started life as a nurse and lived in the remote village of Soba with the Hupla tribe. She learned the local dialect and taught people to read and write in it. Then, with her local team, she translated the bible. In 1989 Soba was the epicentre of an earthquake which killed over 300 people. After the earthquake there was pressure from the central government to move the local people out of the highlands, and Trenear moved with them, living as a refugee in a neighbouring valley.

In 1997, at the request of her church, she moved to the capital, Wamena, to take a broader role.  In 2014, her house in the capital acted as a virtual drop-in centre, the door permanently unlocked. Occasionally things went missing – she lost a laptop in the weeks before my visit – but word got out and it was quietly returned.

Trenear worries more than ever about what she sees around her. Men from local tribes, including the tribal leaders, have been drawn to Wamena by the flow of government money in the form of village disbursements and public service salaries. In the capital, alcohol, drugs and easy sex can trap them for weeks or months while women and children are left to fend for themselves in the village gardens. 

Violence and disease, particularly HIV/AIDS, are epidemic. So many die, says Dutch missionary Marten Van Driel, from black-magic killings, witchcraft, tribal spats and HIV, that 'It's not easy to grow old in Wamena'. Trenear agrees: 'There has been a breakdown of social structure.'

In the 1970s, 'They were often warring, often suffering serious malnutrition. It was no Garden of Eden, but they were living a worthwhile life in their culture,' Trenear says. 'It wasn't a nice life, (but) at least it was coherent: you knew who you were. Now it's like they are in a washing machine. They don't know which way's up.'

A constant 'nervous tension' infects relations between the local Melanesian people and the 'straight hairs' – Muslim Malays from outside Papua – who come seeking economic opportunities and who own all the shops in the highlands and provide most professional services. That tension often spills over into violence, and fuels the ubiquitous desire for freedom from Indonesia.

It's tempting in these physically stunning mountains to think in terms of original sin. Depending on your political view, it may be either the missionaries who interrupted the state of grace, or the Indonesians. Either way, nearly 40 years after Trenear arrived to put her focus on health and education, the standard of both is, if anything, declining – the rate of illiteracy for children under 15 increased from 26% in 2003 to 34% in 2012. 

Something, she says, needs to change. 'We're burying up to three every week. I think it's a crisis: of course it is.'