Gary Smith, 38, was beaten as he walked to Central Foundation Girls' School in Bow, east London, last July.
The gang left him unconscious after attacking him with a metal rod and a brick, Snaresbrook Crown Court heard.
The four all pleaded guilty to GBH with intent and given an indeterminate jail sentence with a minimum of five years.
Simon Alam, 19, of Whitechapel, Azad Hussain, 26, of Wapping, Sheikh Rashid, 27, of Shadwell, and Akmol Hussein, 26, of Bethnal Green, all in east London, were all jailed on Thursday.
Judge John Hand QC said he believed the four remained a danger to the public because of their extreme religious beliefs.
Addressing the defendants one by one, he said: "Your belief is that you carried out a duty to your God and you did so with no mercy.
"If you think that people around you in society present an insult or threat to God then you will not hesitate in attacking again in the way that you have acted." » | Thursday, May 26, 2011
