Yesterday, his distraught mother said her son's actions were completely out of character.
"He's a lovely boy. He has always been Christian in his beliefs, but he's never been a churchgoer.
"Now, I don't know what he's involved in, whether they're some sort of cult or what."
The man went to the cemetery with his two church friends, including Sansom holding a Bible and a copy of Mr Ritchie's funeral programme. He was quickly apprehended by police guarding the freshly dug grave.
Before being taken away in a police car, he urged officers to let him continue his bizarre mission.
"Time is running out," he said, promising to fast-track Mr Ritchie to heaven. "Tomorrow is too late."
One of those with the man was church member Jonathan Sansom.
"He said he wanted to raise the dead and he was going to do it no matter what," Mr Sansom said.
"He's been talking about it for a while. He picked me up from home and just said, 'Today is the day'.
"I didn't know what he was on about. He looked upset, so I went with him."
Mr Sansom said he, too, had joined Fellowship Church last month and the move had been "life-changing".
The church is led by "Pastor Peter". Neither he nor anyone in his congregation would reveal his full name.
Mr Sansom said the pastor had healed his hand after nine tendons were slashed.
"Since Pastor Peter has been praying for me, I've been getting some feeling back in my fingers for the first time. I'm turning my life around. It's amazing."
Pastor Peter said he started the church in June. It met twice a week for service and prayer at Waltham Primary School hall in inner Christchurch and had "60 or 70 members now, I'm not sure".
He denied it was a cult.
"We're just Christians. We believe in Jesus Christ. We pray in the name of Jesus. There's nothing new we do."
He helped heal Mr Sansom's hand but there was "no magic".
"We pray in the name of Jesus Christ. I don't heal people, but God, he heals people."
Pastor Peter invited APNZ to last night's service, which opened with him telling his congregation about the sequence of events that started at Mr Ritchie's funeral.
Churchgoers prayed for the man who banged on the coffin.
Many of the 15 people present chanted aloud in tongues, with eyes closed and palms held upwards. Others stood quietly and read from the Bible.
Pastor Peter said the funeral gatecrasher had been a church member for only three weeks but was "happy, popular".
He accompanied the man to Mr Ritchie's funeral, under the impression the deceased was a friend. He said he couldn't believe it when the man tried to raise the dead.
He apologised to Mr Ritchie's family and said he had urged his parishioner to do the same.
Yesterday, Mr Ritchie's son-in-law, Ross Kiddie, said he and his wife, Jeanne, were glad the man had been apprehended.
"We're pleased that he can now get treatment, or the appropriate justice served."
- APNZ