A member of the bloodthirsty MS-13 gang was sentenced Tuesday to 25 years in prison for his role in the 2016 murder of an upstart fellow gangbanger on Long Island.

Elmer Lopez — who pleaded guilty in March to racketeering for being among several MS-13 thugs who slashed and stabbed Jose Pena for violating gang rules — was slapped with the hefty sentence despite convincing Judge Joseph Bianco that he’d found religion behind bars.

“I have never had, in my life, someone more important than Jesus Christ,” Lopez groveled in throwing himself on the mercy of the federal court in Central Islip. “I beg for forgiveness not only from my family, but from the family of the victim.

“I’ve prepared myself to be a good person in society.”

While Bianco commended Lopez for his “genuine and authentic” remorse, the jurist didn’t hold back in issuing the stiff sentence for the “brutal” crime.

“It is clear you are not the same person that committed this crime or since you have been arrested. I want you to know I give you credit for that,” said Bianco. “[But] you killed Mr. Pena. He lost his life and the sentence has to reflect that.”

The 18-year-old’s mutilated body was found dumped in a wooded area of Brentwood in October 2016, one of several violent outbursts by the infamous Central American gang on Long Island around that time, spurring a widespread crackdown.

“I just want to express to you my sorrow for the loss of your son,” Bianco said, turning to address Pena’s mother. “I understand the suffering and pain you will experience for the rest of your lives.”

Outside court, the heartbroken mom, who declined to give her name, said she was satisfied with the sentence — but would never accept Lopez’s apology.

“No ‘I’m sorry’ or any amount of regret will bring my son back,” she said.