It’s been memorized by countless Sunday school students, displayed on signs at major sporting events, and printed on the bottom of shopping bags and soda cups.

Now, perhaps the most familiar verse in the New Testament has once again been thrust into the public eye after Aaron Hernandez scrawled “John 3:16” on his forehead with red ink before taking his own life.

The Bible verse, regarded by many as the most concise expression of Christian faith, reads in the King James translation: “For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.’’

“If you were going to choose one particular verse to underscore the meaning of the Gospel and Christian truth, that would be it,” said Douglas Webster, a professor of pastoral theology at Beeson Divinity School at Samford University in Birmingham, Ala.

The verse first leapt into popular culture in the 1970s, when born-again Christians started holding “John 3:16” signs at stadiums as a way to spread the Gospel, said Bryan P. Stone, a professor of evangelism at Boston University School of Theology.

The most famous figure of that era was an eccentric named Rollen Stewart, who wore a rainbow-colored wig and danced with a “John 3:16” sign behind the goal posts at football games, home plate at baseball games, and the backboard at basketball games.

Stewart, who was nicknamed Rock ’n’ Rollen and Rainbow Man, was notorious on television well into the ’80s and is credited with popularizing John 3:16.

“He was able to capitalize on the increasing number of games that were televised,” said Joseph L. Price, a professor of religious studies at Whittier College, in Whittier, Calif. “But the contrast between his attire and his conservative sign raised curiosity. How could someone who looked as though he were a hippie have such a standard, conservative verse?”

Since 1992, Stewart has been serving three consecutive life sentences after a bizarre incident in which he locked himself in a hotel room in Los Angeles, held a maid hostage, and threatened to shoot down airplanes. Police arrested him after an eight-hour standoff.

In 2009, the verse once again came to broader attention when the quarterback Tim Tebow wore eye black with the inscription “John 3:16” when he led the Florida Gators to the national collegiate championship over the Oklahoma Sooners. Hernandez, Tebow’s teammate at Florida, played in that game.

Tebow has said that 94 million people Googled “John 3:16” during the game and “it was a pretty cool moment.”

The verse has also appeared on banners and overpasses, and been printed on shopping bags from the clothing store Forever 21 and cups from the fast-food chain In-N-Out Burger.

For Christians, particularly evangelicals, John 3:16 has become perhaps the most important passage in the Bible, Stone said.

“The point is that Christ is salvation, and those who believe in Christ are saved,” he said. “That is the central message of Christians.”

Hernandez had “God forgives” tattooed on his arm, and was known to read the Bible with his coach, Urban Meyer, at the University of Florida. Investigators also found three handwritten notes — whose contents have not been released — next to a Bible in his cell.

Yet it is impossible to know why the 27-year-old convicted murderer and former Patriots player scrawled “John 3:16” on his forehead before he hanged himself with a bedsheet in prison on Wednesday.

But the message resonated with Christian scholars, who theorized that it might have been a plea for forgiveness.

“Aaron Hernandez, through his struggles, either came to Christ, or was already there and was feeling remorse,” said Brian Bolt, a professor at Calvin College in Grand Rapids, Mich., and co-chair of Sport and Christianity, a group of Christian coaches, administrators, and theologians.

Price said that the message of John 3:16 could be seen as a sincere declaration of faith by Hernandez. Or, he said, it might have been “an ultimate protest,” a final act of defiance to use such an affirming verse at the culmination of such a violent life.

Michael Levenson can be reached at [email protected]. Follow him on Twitter @mlevenson.