The court has also imposed a fine of Rs 40,000 each on the convicted persons - Asif Iqbal, Mohammed Shakeel, Irfan, and Mohammed Naseem.
Accused Mohammad Aziz has been acquitted due to lack of substantial evidence.
All the accused are presently lodged in the Naini central jail here and had been charged with attempted murder and criminal conspiracy.
On July 5, 2005, a terrorist had carried out a suicide bombing attempt after breaching the security of the makeshift Ram temple.
Five terrorists subsequently attempted to attack the "Sita Rasoi" and also blew up a jeep near the site.
All the five terrorists were later gunned down by Central Reserve Police Force personnel in an hour-long gunfight, while two civil - Ramesh Pandey and Shanti Devi - were also killed in the cross-fire.
Five assault rifles, hand grenades, cartridges, five pistols, a rocket launcher and jihadi documents were later recovered from the possession of the killed terrorists.
Seven CRPF personnel were also injured in the exchange of fire, three of them seriously.
Delivering the verdict, special judge Dinesh Chand said that those involved in the conspiracy behind the 2005 attack were equally guilty as those who actually carried it out.
The five accused had been arrested after mobile surveillance revealed their involvement in the terror attack.
Of them, Irfan, who hails from Uttar Pradesh's Saharanpur district, was arrested on July 22, 2005 while others, all residents of Poonch in Jammu and Kashmir, were arrested on July 28, 2005.
The four accused had provided logistic and material support to the Jaish-e-Mohammad terrorists.
( With inputs from IANS )