An Auckland man who murdered a church bell-ringer with a machete just metres from the chapel has been jailed for life.

He will serve a minimum non-parole period of 17 years in jail.

Ueta Vea earlier pleaded guilty to killing Laulimu Liuasi, a 62-year-old man who was living on the grounds of the St John the Evangelist Church in Ōtara, Auckland.

Vea, 45, was arrested shortly after the attack on the evening of January 13 this year.

Today in the High Court at Auckland, Justice Simon Moore said Liuasi's family were struggling to come to terms with the enormity of what happened.

"They have seen their family structure collapse," he said.

"Through your [Vea's] actions you have broken this family."

During the attack Vea had severed his victim's spinal cord, the judge said.

"When you were done you didn't lift a finger to help him."

Instead you watched as his life ebbed away before you, Justice Moore said.

"This level of callousness adds another level of culpability."

Justice Moore said he had carefully read letters from Vea's niece and brothers whose heartfelt words shared that they remained confounded that he did not sure his concerns about his marriage.

They too ask for forgiveness, he said.

Vea and Liuasi attended the church with their families and had also previously worked together to maintain the church property, Justice Moore said.

Vea began to suspect the bell-ringer was having an affair with his wife, Veisinia Vea, in November last year.

Vea had discovered sexual messages sent to his wife from Liuasi, who was married himself.

Court documents show Liuasi and Vea's wife were engaged in "flirtatious text communications" and would meet at Liuasi's house on the church grounds.

Vea confronted the pair over the messages several times.

The ongoing tensions led to an intervention between the group and their spouses, which was facilitated by the church priest in December.

Liuasi and Vea's wife denied an affair, but Vea remained suspicious as the sexual texts continued.

In January, the married couple had a heated argument at a church function in Maraetai, as Vea aired his mistrust.

Another confrontation occurred with other members of the congregation over Vea's behaviour before Vea also contacted Liuasi to discuss the fracas.

The next morning Vea's wife asked him to move out of their home - their marriage was over.

Later in the afternoon Vea asked his wife to stop at an Ōtāhuhu home, under the pretext that he was collecting an item for work.

However, he was really collecting his murder weapon - a machete hidden in a cupboard.

Vea wrapped the blade in a blue lavalava and hid it from his wife.

At about 5pm, Vea left the house and walked 3.7km to the church on Ōtara Rd.

Once there he found a hiding spot and tried to observe Liuasi.

Laulimu Liuasi's body was found in a pool of blood on the grounds of the St John the Evangelist Church in Ōtara. Photo / Jason Oxenham

Just before 6pm, Liuasi left his home to ring the church bell and Vea snuck into the house - armed with the machete.

He stood behind a wall in the kitchen, near the door, and waited.

When Liuasi returned he was ambushed.

"Using the machete you rained blows down upon him," Justice Moore said.

Struck several times to the back of the neck, chin, left ear, left shoulder, hand and torso, Liuasi collapsed.

Vea would later recall Liuasi saying "Fia ola", which is Samoan for "I want to live" or "help" during the attack.

Liuasi quickly became motionless as blood pooled around his head while Vea watched him die for about two minutes.

Vea then fled in Liuasi's car, discarding the machete in a wheelie bin next to the rear door.

He travelled to his wife's house and told her he had just murdered Liuasi.

She immediately went to the church with Vea and found the priest.

The three of them entered Liuasi's home and discovered the grisly crime scene.

Liuasi's mouth, however, started twitching and the priest noticed he was still breathing.

An ambulance was called but paramedics were unable to revive Liuasi, while police arrested Vea.

When spoken to by officers, Vea immediately admitted killing Liuasi and told them where he had discarded the machete.