It can't be ruled out entirely but there are other works that contain some of those basic ideas. Lucas says that a lot of his ideas about the Force come from a book called Tales of Power by Carlos Castaneda published in 1974 the same year Lucas wrote the rough draft of Star Wars.
In the outline Lucas refers to the old man’s mystical powers as being like those of “Don Juan”—a reference to The Teachings of Don Juan: A Yaqui Way of Knowledge by Carlos Castaneda, which was first published in 1968, with sequels in 1971 and 1972, followed by Tales of Power in 1975. Castaneda’s fictional Don Juan Matus is like a shaman, with the ability to shape-shift, who teaches the mastery of awareness—to the point where one may keep it beyond death. His mystical influence seems to have been key in transforming Lucas’s concept of the Jedi from a samurai warrior into a more mystical warrior.
The Making of Star Wars (2007) by J.W. Rinzler
Lucas also told Leigh Brackett during their story conferences:
I may bring back Ben eventually; I’ll have to bring back his voice. May also bring back the ghost of Ben, not the person of Ben. Luke is learning the Force through a combination of things, rituals. Some of the Force came from Carlos Castaneda’s book Tales of Power [1974].
The Making of The Empire Strikes Back by J.W. Rinzler
Among the sorcerer's many teachings is the idea that we are all "luminous beings".
"Today I have to pound the nail that Genaro put in, the fact that we are luminous beings. We are perceivers. We are an awareness; we are not objects; we have no solidity. We are boundless. The world of objects and so- lidity is a way of making our passage on earth convenient. It is only a description that was created to help us. We, or rather our reason, forget that the description is only a description and thus we entrap the totality of ourselves in a vicious circle from which we rarely emerge in our lifetime.
Tales of Power (1974) by Carlos Castaneda
Those words are put into Yoda's mouth in The Empire Strikes Back.
YODA:
And well you shouldn’t. For my ally is The Force. And a powerful ally it is. All of life feeds it and makes it grow. Its energy surrounds us and binds us. Luminous beings are we… (Yoda pinches
Luke’s skin) … not this crude matter.
The Empire Strikes Back Fourth Draft (October 24, 1978) by Lawrence Kasdan
That he chose to name his version of what Castaneda’s sorceror was teaching as something that rhymed with Kirby's "The Source" is a coincidence. "Force," as a word for a kind of supreme being is said in Arthur Lippsett's 1964 film 21-87. The film is on YouTube and the quote begins at around 3:32.
Many people feel that in the contemplation of nature and in communication with other living things, they become aware of some kind of force, or something, behind this apparent mask which we see in front of us, and they call it God...
Lucas was a huge fan of 21-87.
Lucas's favorite films remained the shorts made by the National Film Board of Canada, particularly 2187, an abstract film made up of news footage with image and sound juxtaposed out of context. Halfway through the film, a man wakes up and says, "You're 2187, aren't you?" and smiles, the only dialogue in the film. Lucas loved it: "I said, 'That's the kind of movie I want to make — a very off-the-wall, abstract kind of film.' It was really where I was at, and I think that's one reason I started calling most of my [college] movies by numbers. I saw that film twenty or thirty times."
Skywalking: The Life and Films of George Lucas (1983) by Dale Pollock
Lucas would later reference 21-87 in Star Wars.
THREEPIO
Level five, Detention block A-23, cell 2187… He’s still alive… but his condition is reported as critical.
Adventures of the Starkiller (episode one) “The Star Wars” Second Draft (January 28, 1975) by George Lucas
Lucas first tried writing the Force into his first feature, 3 years before the debut of New Gods.
"There must be something independent,” said THX 1138. “A Force.” Lucas wrote those lines in 1968, as he was adapting THX 1138 4EB into what would be his first-ever feature film. The echo from Arthur Lippsett’s 21-87 could still be heard. Sometime in the following year, he decided to cut the Force scene from his THX script. But the Force would continue to flow through him, demanding to be born as a concept.
How Star Wars Conquered the Universe (2014) by Chris Taylor
Darth Vader, being a masked villain, is in line with a trope common to the 1930s serials Lucas was inspired by. The plots of a lot of them concerned the hero's attempts to learn the true identity of the bad guy causing all the problems. One these serials The Fighting Devil Dogs has a masked villain called The Lightning that the book The Secret History of Star Wars asserts was an inspiration for the development of Vader.
Ralph McQuarrie says that he got the idea for the mask because he thought Vader would need it to breathe in space as they are boarding the ship. McQuarrie also said that Lucas told him to add a samurai helmet. So while it's possible The New Gods was consulted as well it appears the similarities may be the result of parallel thinking.
I reminded George that the first time we see Vader, he’s boarding one spaceship from another, and I asked, ‘How’s he going to breathe out there in space?’ So my illustrations show a breathing mask with a downward-curving snout and big goggles. John Barry and his designers developed it further with a mask that gave Vader a monumental stature, and I think George felt that keeping Vader always in his mask would be fascinating – like an actor in an old Greek tragedy. But it all came to pass because I thought he needed a mask to breathe.
Star Wars: From Concept to Screen to Collectible (1992) by Stephen Sansweet
As for the father twist, there's prior art for that as well including the aforementioned The Lightning. He is revealed to be the father of the lone female character. There is another movie from 1932 called Tombstone Canyon that has the most dead on similarities.
The hero comes to town because an old man has written him telling him he has information on who his parents were. In the meanwhile a mystery villain known as The Phantom Killer is causing trouble for a local rancher and his gang. The old man, described as a "queer old fella" (vs "strange old hermit") is killed before he can tell the hero what he knows. At the end the hero and The Phantom Killer learn that they are father and son. The father is fatally wounded saving his son's life and the last thing he wants to do before he goes is to look at his son.
A film critic named Michael H. Price claims that it was on the basis of this movie that he knew the father twist was coming well before the credits rolled on his first viewing of Star Wars in 1977. So again while Kirby's influence can't be ruled out here there's other precedents that Lucas could have pulled from.
"I had sensed about three-quarters of the way through my first viewing of Star Wars (1977) that this cosmic bad guy, Darth Vader, was going to turn out in Empire to be the long-lost father of Luke Skywalker, the wet-eared hero. That "paternity stunner," as the tabloids would call it, is common knowledge today, thanks to an insatiable popular appetite for the Star Wars pictures on video."
"There was no great prescience at work in my case, just a baby boomer childhood spent watching the Saturday-matinee horse-operas of John Wayne, Bob Steele and Ken Maynard: Anybody who ever sat through Tombstone Canyon (hero, while searching for his long-lost daddy, must battle a marauding "phantom") in its umpty-leventh TV rerun could smell the Darth Vader revelation coming from a mile away."
Michael H. Price writing in the Fort Worth Star-Telegram February, 1997