Stephen Harmon, a member of the Hillsong megachurch, passed away on Wednesday at the Corona Regional Medical Center outside Los Angeles.
The 34-year-old was being treated for Covid and pneumonia and had been a vocal opponent of coronavirus vaccines.
In June, he tweeted: “If you’re having email problems, I feel bad for you son. I got 99 problems but a vax ain’t one.”
Mr Harmon then went on to publicly document his illness and treatment on Twitter and Instagram after being hospitalised later that month.
His death was announced by Hillsong founder Brian Houston who shared “the devastating news that our beloved friend Stephen Harmon has passed away from Covid. Heartbreaking.”
In the days leading up to his death, Mr Harmon gave an emotional account of his fight to stay alive.
Posting online, he told how he was “struggling to function”, “on max oxygen” and questioned if he should go on a ventilator, reports MailOnline.
“Please pray y’all, they really want to intubate me and put me on a ventilator,” he said.
“Even the slightest movements and my heart rate skyrockets and oxygen dependency increases. and please, I’m not asking for anyone’s opinion on intubation, I’ll make my own choice, I’m asking for prayer.”
In a follow up, he added: “If you don’t have faith that God can heal me over your stupid ventilator then keep the Hell out of my ICU room. There’s no room in here for fear or lack of faith #ThingsIAmAboutToScream.”
His final tweet on Wednesday revealed that he had decided to go under intubation.
“I’m choosing to going under intubation, I’ve fought this thing as hard as I can but unfortunately it’s reached a point of critical choice and as much as I hate having to do this I’d rather it be willingness than forced emergency procedure. Don’t know when I’ll wake up, please pray.”
The anti-vaxxer was described as a Hillsong College graduate and a faithful member of the Hillsong congregation in California.
In a heartfelt comment on Instagram, Mr Houston said: “He was one of the most generous people I know and he had so much in front of him.
“He would always turn up to our grandkids soccer games and he will be missed by so many. RIP.”
Covid infection rates are rising in nearly 90% of US jurisdictions which is partly due to the rapid spread of the Delta variant.
Outbreaks are taking place in areas of the country that have low vaccination coverage, according to the Centers for Disease Control and Prevention.