Mel Gibson has stated the faith-oriented basis of his new film Hacksaw Ridge by explicitly comparing the Christian-inspired bravery of conscientious objector Desmond Doss with the kind of comic-book characters previously played by his lead actor Andrew Garfield. Speaking to journalists at the Venice film film as Hacksaw Ridge received its world premiere, Gibson said: “Desmond attributed his actions to a power greater than himself, and the difference between a real superhero and a comic-book superhero is that real superheroes didn’t wear any Spandex.”

Hacksaw Ridge is Gibson’s first film as director in a decade, since 2006’s Apocalypto, and it is a sometimes gruesome study of Doss’ time in the military during the second world war, when he became the first conscientious objector to be awarded the Medal of Honor, in recognition of his bravery as a combat medic during the battle of Okinawa. Doss, who died in 2006, was a Seventh Day Adventist and refused to carry a gun, but served as a company aid man in 1st Battalion, 307th Infantry in the bloody assault on the island.

Gibson reiterated his interest in Doss’ religious commitment: “It’s undeniable what the essence of Doss was: he was a man of great courage and strong conviction, and strong faith; to go into a battle zone like that – which the Japanese called it ‘steel rain’, with the artillery and lead flying around – to go into that armed with only your faith, your faith has to be strong in you. That’s an undeniable part of the story I found really inspiring.”

Andrew Garfield as Desmond Doss in Hacksaw Ridge. Photograph: PR

A visibly nervous Gibson briefly referred to the difficulties his career has encountered since since 2006, describing his relationship with Hollywood as “survival” and saying: “Sometimes you take a big step backwards, I’ve done it ...For one reason or another, maybe it’s where you are in your life.” It was after Apocalypto had finished shooting in 2006 that Gibson incurred the infamous traffic stop for drunk driving that ended with him aiming antisemitic abuse at a police officer; his position was further derailed after a tape emerged of a racist tirade at his then-partner Oksana Grigorieva in 2010.

Hacksaw Ridge represents a high-stakes comeback for Gibson and, in Venice, the director was clearly anxious to avoid any other controversy, sidestepping a question as to whether film, with its gun-hating protagonist, was taking sides in the US’s gun control debate. He said: “The man who refuses to touch a weapon, and do something much higher than something as venal as killing in a war; it’s a very high calling ... You have to love the warrior, and give him homage and honour him. I hope this film does that.”

On a more technical note, Gibson was asked about the extended battle scenes, which show the repeated attempts by US army units to take Okinawa, with enormous casualties incurred on both sides. In several of his films, including Braveheart and Apocalypto, Gibson has displayed a particular proficiency in filming combat, and said: “The important thing about depicting battle on screen, is to be clear with it, and not confusing. You give the impression of chaos, but be absolutely clear what it is you want the audience to see and extract from the sequences. It’s all about screen direction and knowing who the players are; you have to approach it almost as a sporting event. It sounds mercenary to say that about battle; but if you are not able to follow the strategies, somehow [the audience] become less involved.”

The Venice film festival continues until 10 September.

