Billy Stanley can still vividly recall the last time he spoke to his stepbrother, Elvis Presley.

It was Aug. 14, 1977, and the singer was proudly demonstrating his new karate knives. While the two were sparring, Stanley threw an unexpected punch, causing Presley to quickly react. Stanley hurt his finger and a blood blister quickly formed.

"He saw that he hit me, so he immediately dropped the knives, grabbed my finger and walked me to the bathroom," Stanley, who recently wrote his new book "The Faith of Elvis," chuckled to Fox News Digital. "We were standing by the sink, facing this huge mirror. Here was Elvis, making a big deal out of this, like he was going to have to do surgery or something. Meanwhile, I’m just standing there in amazement, smiling at him."

Billy Stanley's new book The Faith of Elvis

Billy Stanley's new book, ‘The Faith of Elvis,’ focuses on the late star's deep connection with God. (Thomas Nelson)

However, the mood became somber. Presley quietly asked, "Do you believe God forgives us for all our sins?" A stunned Stanley replied, "Well, yeah, I mean, we’ve talked about this for almost 17 years, Elvis." Presley replied, "I just wanted to hear you say that, Billy."

ELVIS PRESLEY'S FINAL MONTHS WERE PLAGUED WITH PHYSICAL PAIN AS HE EMBARKED ON GRUELING TOUR, AUTHOR CLAIMS

The conversation then turned to the future. According to Stanley, Presley was eager to make serious changes in his life. He was going to get rid of his longtime manager Colonel Tom Parker and fire some of his employees. Stanley claimed Presley was hopeful that he would consider leaving behind his job as an assistant jet mechanic at the airport and work for him again. The talk then turned to love. Presley assured his younger sibling that one day he would find it, noting he had been in love "twice," without giving any names.

"[He said], ‘You couldn’t even guess, Billy," Stanley recalled.

Elvis and Priscilla Presley

Elvis Presley and Priscilla Presley were married from 1967 until 1973. (Courtesy of Billy Stanley)

Presley then said he was going to go read his Bible. Stanley assured Presley that he would see him Aug. 16. Presley replied, "OK, I love you." As Stanley headed home, he thought about turning back to tell Presley he loved him back. He changed his mind, though, reminding himself they would meet again in a matter of days.

It was the last time Stanley saw Presley alive. The rock ‘n’ roll star passed away on Aug. 16, 1977, at age 42.

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

"I wish I had gone back," he told Fox News Digital, choking back tears.

Over the years, numerous books have focused on the brief life of one of the most iconic figures in American music. Stanley himself wrote a memoir titled "Elvis, My Brother" in 1989. Earlier this year, Baz Lurhmann’s biopic "Elvis" sent temperatures rising at the box office. This time, however, Stanley wanted to focus on Presley’s relationship with God. He said a near-death experience in 2018, or what he described as a "near God experience" involving "the widowmaker" compelled him to explore Presley’s faith.

Presley’s father, Vernon Presley, remarried in 1960 after losing his first wife Gladys in 1958. With the union, Presley gained three little brothers. Stanley was 7 years old at the time.

"[I remembered] he picked all three of us up at the same time and said, ‘I’ve always wanted a little brother. Now I got three,’" Stanley shared. "We didn’t know who he was, but he talked to us the rest of the night and tucked us in bed. And the next morning, he came running in like a fire drill, ‘You gotta get up!’ We go out to the backyard and there are three of every kind of toy you could think of. He had a store open up after we went to bed."

WOULD ELVIS PRESLEY SURVIVE CANCEL CULTURE? FORMER WIFE PRISCILLA WEIGHS IN

Elvis Presley's stepbrothers

Elvis Presley gained three stepbrothers when his father, Vernon Presley, married Davada ‘Dee’ Stanley in 1960. (Courtesy of Billy Stanley)

The brothers gained more than just presents that day. Stanley said Presley taught them the importance of saying their prayers every day. They gave thanks every evening for their blessings, and Presley dedicated much of his time to reading the Bible, taking notes and highlighting scriptures that spoke to him. Stanley said those teachings became prominent when he later worked for him on the road for nearly two years. One of his tasks was to carry his Bible, no matter where they went.

"A lot of people don’t realize that after every show, he would unwind by singing gospel songs until the sun came up," said Stanley. "He was in touch with the Lord. A lot of people said, ‘Well, he did this and that.’ [But] we all fall short. We’re all human. As Christians, most of us live under a magnifying glass. Well, Elvis lived under a microscope because he was a big star. It was tough. But the way I like to put it is… [he] had the devil on one shoulder and God on the other. And there was a constant battle going on in his head."

By the mid-‘70s, Presley was struggling with his physical health. He had developed a dangerous dependence on prescription drugs. His marriage to Priscilla Presley came to an end in 1973. Still, Stanley said Presley found comfort in God’s words during tough times.

Elvis Presley's handwritten Bible

One of the handwritten messages in a Bible that used to belong to Elvis Presley. It reads, 'To judge a man by his weakest link or deed is like judging the power of the ocean by one wave.' (Photo by Dave Thompson/PA Images via Getty Images)

"He would just dive into the Bible and read it," said Stanley. "Any experience that we all have is in the Bible… it will comfort you. I think the biggest thing everybody has a problem with is forgiveness. But God forgives. All you have to do is ask for it. But we have a hard time forgiving ourselves. Elvis often spoke about how God forgives us. He took great comfort in that… Once you start believing Jesus came and died for your sins, your actions will change. You will try to stop doing the things that aren’t good for you."

LISA MARIE PRESLEY SAYS SHE FELT LIKE A 'PARIAH' AFTER LOSS OF SON BENJAMIN

"He would tell me, ‘Billy... if we focus on helping somebody else… it’s good for your soul to do that,'" he continued. "The Bible says the Lord loves a generous giver and [Elvis] was the most generous giver I’ve ever met. Whenever you’re feeling lonely or feeling like nobody loves you… you see that the devil’s playground is your mind. But helping somebody else? It takes away all that self-doubt and fears you have going on in your life. That’s what we’re all put here on this Earth for. Elvis believed that."

Presley was concerned about other celebrities who criticized America during the Vietnam War. Presley was drafted into the Army in 1957 during the height of his career.

Elvis Presley tour in Germany

Elvis Presley salutes for a portrait during his tour of duty in Germany in February 1959. (Photo by Dave Thompson/PA Images via Getty Images)

"A lot of people, when they talk about being a true patriot, they talk about being a hawk," said Stanley. "Well, Elvis was an eagle. He went and served his country… He was drafted, but he proudly served. He loved America. He used to say it was the greatest country in the whole world. He would say, ‘We could never fail because in the Pledge of Allegiance it says, ‘One nation under God.’ And as long as we stay that way, we will remain strong.’ During the Vietnam War, he couldn’t understand how some people wanted to leave America. Our leaders are what got us there. And even if they were wrong, he would still follow our leaders."

"There were a lot of entertainers who were saying, ‘I want to leave America.’ Whenever Elvis saw that on the news, he would say, ‘Well, I’ll pay for your plane ticket to go if you want to leave.’"

"That bothered Elvis," Stanley continued. "He didn’t think it was right for an entertainer to speak against the country because the only reason they’re able to do what they do is that they’re in this country… In this country, you have the freedom to pursue your dreams. He was a true patriot. He loved God and his fellow man."

PRISCILLA PRESLEY SAYS ELVIS WOULD HAVE ‘LOVED’ NEW BIOPIC: ‘IT’S PERFECTION’

Stanley said that at times, Presley would hint that his time on Earth was short. He pointed out how on his mother’s side of the family, many seemed to pass away at a relatively young age.

Rock and roll musician Elvis Presley during a press conference

Rock ‘n’ Roll musician Elvis Presley during a press conference after his first performance at the International Hotel in Las Vegas Aug. 1, 1969. Billy Stanley said Presley had big plans shortly before his passing. (Photo by Michael Ochs Archives/Getty Images)

"It was always in the back of his mind," said Stanley. "One of the lessons he taught me is to try to make the best out of every day because we’re not guaranteed tomorrow. Every day is an event and that’s how he treated it. He made the most out of every day. He lived it like it was his last day."

Today, Stanley said he enjoys relieving his memories with Presley and often feels his presence. Stanley is married to his high school sweetheart, and they reside in Memphis, Tennessee, just a few miles from Presley’s Graceland.

"What we saw on his entertainment level was maybe 20-30 percent of what he really was," said Stanley. "He was far greater than that… he was a God-fearing patriot and a great big brother. The things he taught me about life, I’ve never forgotten."