However, they claim Travolta also has a "dark side" and accused him of being "reckless".
The Daily Beast reported former Scientologists had told the publication the couple has remained largely unscathed because Preston is a big Scientology devotee and she "anchors" Travolta.
"Kelly is a much more dedicated Scientologist than John," Mike Rinder, a former Scientology spokesman, reportedly told The Daily Beast. "Scientology dictates every choice in life and informs every decision a Scientologist makes."
Mr Rinder added it would be a "catastrophe" if Travolta or someone who was part of the church were to come out as gay because the church itself was "anti-gay".
During a panel discussion at the Cannes Film Festival, where Travolta is promoting his critically-panned new film Gotti, he told the audience Scientology had been filling him with enduring confidence to mount career comebacks.
"I practice Scientology, and we do very simple things to get ourselves in better shape: take care of yourself, get good sleep, be better parents, be productive, be motivated," Travolta told the audience. "It sounds simple, but they all contribute to your wellbeing."
Travolta has been a Scientologist since 1975 and other prominent Hollywood stars including Tom Cruise and The Handmaid's Tale star Elisabeth Moss also adhere to the controversial belief system.
And, according to The Daily Beast, former church members have claimed his religion has helped protect him from the allegations which have been splashed across global media outlets.
Karen de La Carriere, a former Scientology executive said the church's intense instruction includes training to not believe what is said in the media.
"The church has a very intense indoctrination to prepare you for anything you might hear," The Daily Beast reported her as saying. "It's like a pre-emptive strike in case something uncomfortable comes up.
"Kelly's been trained to not believe what she hears in the media. She's been trained to think that these are evil people making things up."
Another former Scientologist, Jeffrey Augustine, said Travolta is losing interest in Hollywood but added that the actor could never leave the church.
"John loves aviation more than Hollywood but because of Kelly he'd never leave Scientology," Augustine told The Daily Beast. "He loves his family. He's just got a dark side and he's reckless. But he really has no reason to want to leave the church.
"People at his level never see the ugly side of the church. Plus he's got OSA (Scientology's Office of Special Affairs) as his own private Mafia if he gets into trouble."
The alleged case of "sexual battery" involving Travolta is said to taken place at the The La Quinta Resort & Club in Palm Springs on February 15, 2000, but the police documentation only came to light in November.
The masseur — who was not identified in the report — "consented to the touching after Travolta told him he was attractive, after Travolta said he had been excited, after Travolta removed his towel, and while Travolta was naked along with (redacted) in the steam room," according to the report published by gossip site RadarOnline.
Travolta has not commented publicly on the release of the police report. He was previously the subject of a $2 million law suit by two unnamed masseurs in 2012.
