Tanveer Ahmed stabbed Asad Shah outside his store in the Shawlands area in Scotland.
Mr Shah, 40, an Ahmadi Muslim who moved from Pakistan to Glasgow in 1998, was discovered outside his shop on Minard Road on March 24 this year with stab wounds and taken to the Queen Elizabeth University Hospital, where he was pronounced dead.
He suffered multiple broken bones and the base of his skull was fragmented in a way more commonly seen in victims of road traffic accidents, with "numerous powerful blows" to his head and back, the High Court in Glasgow heard.
"This was a truly despicable crime, motivated, it seems, by your sense of offence at a man's expression of his religious beliefs, which differ from yours. Let me be clear - there's no justification whatsoever for what you did," Judge Lady Rae said, as she deferred sentencing until August 9.
The court was told that when Mr Ahmed was interviewed by police he said his actions were motivated by Mr Shah's disrespect to Islam.
Ahmadis differ from the majority of Muslims in that they do not hold that Muhammad is the final Prophet, the court was told.
It emerged in court that Mr Ahmed, a cab driver, was in Glasgow a couple of days before the murder with a friend who knew Mr Shah and showed his Facebook page.
The shopkeeper had uploaded hundreds of videos about his spiritual beliefs to Facebook and YouTube, most of which were filmed behind the counter of his shop.
