He escaped the clutches of Branch Davidian leader David Koresh just months before the cult's fiery end at Waco, Texas.
Now, New Zealander Ualesi Vaega has spoken for the first time of the loss of his family, among the 76 people who died in the two-month siege in 1993.
Vaega, who lives in Northland, has described Koresh's entrancing power, which left him with voices in his head after leaving the cult.
The Kiwi lost his elder brother and sister-in-law in the fire, which destroyed the complex and those inside.
He spoke as part of an Inside New Zealand documentary, How To Spot A Cult, which screens this week on TV3.
The US Bureau of Alcohol, Tobacco, Firearms and Explosives raided the Waco ranch in 1993.
The subsequent siege by the FBI ended with the burning of the compound in McLennan County.
Koresh, 54 adults and 21 children were found dead after the fire.
Vaega said he had learned hard lessons from his involvement with the cult.
"If I was to do it all over again and learn these lessons, I would. I'm just assuming that now, that that is what I'll do. There is no other way to learn painful lessons but to walk through it."
Vaega was introduced to the Davidians through his brother, who was involved in the cult in Hawaii. He travelled from there to Texas, wanting to learn more about the movement.
His induction involved little sleep and a lot of preaching while the Davidians repeatedly pushed messages considered important to the cult.
"And I had to sit there and observe. Just had to find out what it is to be human under those circumstances ... what in me was happy ... what in me needed to change. It's a struggle when you don't get much sleep."
Those who formed the core of the Davidian movement became like family, "just like brother and sister, mother and father", he said.
"It was only when I came back ... every time I would sleep, you'd hear voices. I could hear people's conversation and it would be replaying in my head."
Vaega eventually found he was able to break away from the oppressive power of the cult, leaving just before the siege began. It was too late for his family.
"To see a lot of my family and friends die - all I saw was that their will to think consciously away from that environment would have made a huge change."
The lessons Vaega said he took from his experience included the ability to be a more loving person, and the warning that cults could have huge power over groups of people.
"It tells me that millions of people could die due to one person's vision."