One of the girls described Gough as "constantly aroused".
She said he would approach her from behind in class under the pretence of helping but would instead rub his penis against her.
Another victim said he wore an apron to disguise his erection.
He would play with her bra strap and peer down her top in front of a class full of students.
"It made her feel scared and vulnerable and she was ashamed it happened in front of classmates," Judge Kevin Glubb said.
"She said you would stare at her chest from elsewhere in class... it felt like she was standing there naked."
The other two victims informed police of incidents that had taken place on camping trips.
One said she had been coaxed into the bush, away from her group, where Gough had forced her to commit sex acts.
While he pleaded guilty to the four counts of committing indecencies against the girls, his lawyer Roger Chambers said he could not remember the abuse.
"At his age he doesn't have a very clear recollection of what occurred," he said.
Gough, who limped into court using crutches, was a "model prisoner", according to Mr Chambers.
The court heard about the impact on his victims in their own words.
"I was a good Christian girl and you took advantage of me for your own selfish sexual gratification," said one.
Others talked about how their relationships with others and academic achievement had suffered; another said she felt "robbed of a normal life".
"What's clear is the ripples from your offending have run out wider and had ongoing lasting effects on those young people," the judge said.
Judge Glubb, who also sentenced Gough in 2014, described his previous offending as "persistent, relentless and repeated".
He said the defendant was an active member of the church and had gained people's trust through his reputation as a pillar of the community.
The court heard also heard how he had made a peep hole under a house so he could watch children in the shower.
Judge Glubb said the offending was carefully orchestrated and Gough "used [the children] as sexual toys".
"It's a total disgrace," he said.
Gough's prison term will end in May 2019.
Victim: "I hate him"
Herald reporter Anna Leask spoke to one of Gough's victims from his previous trial in 2014. She spoke about how she had tried to take her own life and had struggled with alcohol:
One of Gough's victims told the Herald his offending had ruined her life.
She said people around her knew what he was doing, but never intervened. She struggles with that daily.
"It was horrible. My mother knew this was going on, the neighbours knew, other relatives ... no one ever did anything," she said.
She also believed there would be more victims and was pleased his name suppression had lapsed so his crimes could be "put out there finally".
"I have just about died five times in the last year. I've overdosed, I'm just so depressed, so pissed off with life -- I'm just sick of it," she said.
"I hate him. He did this to me from when I was a little girl ... I just want what he did acknowledged."
The victim said she was angry at Gough, whose "disgusting"offending had pushed her to drugs, alcohol and an eating disorder.
"I've been an alcohol and drug addict since forever. I had good jobs, I've been a good mum but what he did impacts on my life hugely."
She said his guilty plea was "a relief", but it didn't take her pain away.
"Two months ago I tried to take my life ... it was pretty bad, they thought I was going to die this time. It's pretty hard. He has totally and completely ruined my life, I'm a complete mess. I drink to forget ... I've been to rehab four times, I got sectioned last year because of my drinking. I'm so f***ing angry."
She said Gough had apologised to her, but his words meant nothing.
"It wasn't just the sexual abuse, he had me living in terror. I will never get over that."
The victim encouraged anyone else who had been abused to come forward.
"Just set yourself free, tell someone. If you think it's happening to someone else, do something," she said.
She wanted to thank the police for making the process of bringing Gough to justice easier for her than she initially expected.
"The police have been amazing. They have been so lovely to me.
"What he did was not fair. He should be jailed for the rest of his life."
