Hotel porter Benjamin Lewis, 25, of Totton, near Southampton, Hampshire, was convicted of religiously-aggravated harassment, at Southampton Crown Court on Friday.
His friends Scott Bower, 26, who is unemployed, and Mr Lewis’s girlfriend, 19-year-old student Natalie Gibson, both of Totton, were also found guilty of the same charge.
The three harassed Reverend Christopher Rowberry, his wife Karen and children Hannah, 15 and Simon, 17.
They made scores of abusive phone calls and howled at the vicar from a graveyard next to his church St Mary The Virgin, in Eling Hill, Totton, between October and December last year.
‘I believe in vampirism’
They also left obscene pictures, including one of a disembowelled Christ, on a church notice board.
Lewis earlier told the court: “I have been interested in blood drinking – I believe in psychic vampirism.”
Judge John Boggis QC warned the three that they would face custodial sentences
He said: “It’s your intolerance that is appalling.
“I am quite satisfied Lewis you have manipulated the other two.”
Sentencing was adjourned until 14 November for pre-sentencing reports and for a psychiatric report to be prepared on Lewis.