Mr Justice Teare made the comments at Sheffield Crown Court as he sentenced Jonathan Bowling to life in prison for the murder of lay preacher Alan Greaves, 68.
Bowling, 22, battered devout Christian Mr Greaves around the head with a pick-axe handle as the pensioner walked to play the organ for Midnight Mass at St Saviour’s Church in High Green, Sheffield, on December 24 last year.
The father-of-four suffered catastrophic head injuries and died three days later in hospital.
Another man, Ashley Foster, 22, was found guilty yesterday of Mr Greaves’ manslaughter and was jailed today for nine years.
The judge told Bowling and Foster: “Why you wished to inflict violence on another human being on Christmas Eve is known only to you. But you did it.
“You chose your victim at random. Alan Greaves happened to be in front of you, on his way to serve the community, as he had always done, and you decided to inflict violence on him.”
The judge said the attack took place on Christmas Eve “on what is usually one of the happiest days of the year”.
He said: “Neither of you knew Alan Greaves. He had done nothing to provoke the attack on him.
“He was merely walking to church to help his local community celebrate Christmas.
“His wife, his family and his community have suffered a tragic and horrendous loss.”
There was no repeat of the dramatic scene seen in court after yesterday’s manslaughter verdict on Foster. Bowling had admitted murder at a previous hearing.
Mr Greaves’ widow, Maureen, said she was “happy” with the sentences.
Outside court, she said: “I really am extremely pleased with the result today.
“To think Ashley’s got nine years is the very best we could have got in the circumstances of the manslaughter.
“To think that Jonathan’s got 25 minimum and to think he’ll probably never come out, I really am wonderfully pleased with the result.”
She told reporters she would not read a letter Bowling had written to her.
“To put it into my hands the day he was going to get sentenced, I didn’t think it was very appropriate,” she said.
“If he was going to write me a letter he should have written it a long time ago.”
Mrs Greaves said she had given the letter to Detective Superintendent Matt Fenwick, of South Yorkshire Police, to look after in case she changes her mind.
The judge said it was Bowling who inflicted all the blows on Mr Greaves, leaving him with head injuries normally seen in people involved in serious car crashes or falls from great heights.
He said he accepted, from the jury’s manslaughter conviction, that Foster did not take part in the attack physically and he accepted the pick-axe handle was the only weapon used.
The judge said Bowling hit him at least twice with “extreme force”.
He said Mr Greaves was an “elderly man who had done nothing to justify or explain the attack on him by Jonathan Bowling.”
He said to Foster: “You left him in his injured condition alone and without assistance.”
The judge went on: “The violence was gratuitous. It took place on the streets of Sheffield at night.
“You participated in an attack which resulted in the death of a man merely on his way to serve his community.”
The judge then praised the “dignity, courage and humanity” of Mrs Greaves and her family.
Earlier today, Mrs Greaves, 63, spoke of her forgiveness for Foster and Bowling.
She told Daybreak: “It is truly through the grace of God, the love of God, that I have been able to forgive these people - to forgive Ashley and Jonathan - and to leave them in his hands, and to continue to do just what I have committed myself to do.”
Mrs Greaves, who is an evangelist with Church Army, described how she made this decision as she sat with her husband in hospital, knowing he was going to die.
She said: “I held Alan’s hand and I said to God ‘please take the men who have murdered Alan, I want to place them into your hands, I want you to deal with them and I want you to give me the grace to truly forgive them’.
“And that’s what I did.”
She watched the two men carefully today as they sat in the dock surrounded by prison officers.
Foster, who was wearing a blue jumper and blue trousers, sat with his head down for most of the hearing, occasionally glancing at his girlfriend in the public gallery.
Bowling sat looking straight forward, wearing a blue jumper, blue jeans and sporting a large tattoo on the right-hand side of his neck.
He was handcuffed in the glass-fronted dock and also shackled to one of the prison officers. He showed no emotion.
The court heard that Foster and Bowling had left a family gathering earlier on the evening of Christmas Eve last year.
According to prosecutors, they were angrily stalking the streets of High Green looking for someone to attack. If they had not killed Mr Greaves, a retired social worker, it would have been someone else, the jury was told.
Senior police officers said the pair were simply out “looking for trouble”.
Prosecutor Robert Smith QC told the court today: “It was a crime without motive.
“He was killed for no reason other than that he had been identified as a suitable victim.”
Earlier today, the court heard how Bowling of Carwood Way, Pitsmoor, Sheffield, has a number of convictions for violence dating back to his teens.
In 2005 he head-butted a 48-year-woman after she complained about him throwing snowballs at her windows.
A year later, when he was 15-years-old, he was given a two year detention order after he attacked a jogger in Chapeltown, Sheffield, leaving his victim with serious head injuries, including a suspected broken cheekbone.
Bowling was then convicted for brandishing a hammer when a police officer stopped him then threatening a woman with a hammer in a separate incident.
In 2008 he and a girl pinned a 14-year-old boy to the floor before he kicked and punched the teenager in the ribs.
The court heard he had served a number of detention orders in relation to these offences.
Foster, of Wesley Road, High Green, had no previous convictions for violence.
Foster and Bowling, who were both unemployed, had known each other since their early teens when Bowling’s father was in a relationship with Foster’s mother. They have been described as stepbrothers.
Mr Greaves was a social worker for 35 years before he retired about eight years ago. He and Mrs Greaves had been married for 40 years and have four children and two grandchildren.
He was devoted to music and the church - playing the organ at different services around Sheffield - and also singing in choirs.
Mr Greaves took part in a range of other community activities, including playing piano in the local primary school, serving as a school governor, helping in a charity shop and even launching a food bank for people in High Green.