John Bailey, 76, assaulted three girls under 14 - one as young as four - over a 27-year period.
The ex-Church of England minister, of Kippax, Leeds, pleaded guilty to 25 charges of indecent assault at a previous hearing on August 29.
Lincoln Crown Court heard that the married former Diocese of Lincoln clergyman committed the offences between 1955 and 1982 and wrote letters to his victims, begging them not to go to the police.
Bailey had recently been diagnosed with Alzheimer's and vascular dementia and the judge admitted the pensioner would find it "harder than many" in prison.
He assaulted his first victim over a four-year period in the 1950s, then abused two more between the mid-1970s and early 1980s.
Bailey, wearing a grey jacket, dark blue shirt and a blue and white spotted tie, sat in the dock and looked straight ahead he was sentenced on Thursday.
Judge Simon Hurst told him: "I have had the advantage of reading victim impact statements and it is clear that in their different ways, they were all profoundly affected by your abuse of them.
"You did it for no other reason other than to gain sexual gratification for yourself."
Bailey was arrested during Lincolnshire Police's Operation Redstone, which started in October 2015 and followed a review of past safeguarding cases by the Diocese of Lincoln.
Chris Moran, defending, said Bailey clearly wanted to "express remorse" but at the same time admitted there was "a degree of somebody who doesn't want to be reported to police".
Mr Moran said: "Other than this offending he is a man who is known as a caring, responsible individual - a dependable one in many ways."
Bailey was told he would have to register his movements with police for the rest of his life, under the Sexual Offences Act.
After the sentence, Detective Superintendent Richard Hatton said: "The sentence today reflects the breach of trust that John Bailey has shown in terms of his position as an ordained minister in the Church of England.
Mr Hatton said the investigation was one of several into the recent safeguarding concerns raised by the Dicoese of Lincoln.
In a statement issued afterwards, the Bishop of Lincoln, the Rt Rev Christopher Lowson, said: "It is hard to express the impact that John Bailey's appalling crimes must have had on the lives of the survivors of his abuse and on their families. I wish to pay tribute to their courage in bringing him to justice.
"I would also like to thank the police for their work on this case and for their continued commitment to Operation Redstone, which was established in response to detailed case reviews carried out by the bishop's safeguarding team.
"I want to reassure everyone that our safeguarding work in the diocese includes mandatory training and background checks for all clergy and church officers.
"The public are fully entitled and deserve to expect the highest conduct from clergy, who promised solemnly at their ordination to order their lives according to the way of Jesus Christ.
"We continue to work in partnership with the police and statutory authorities and will leave no stone unturned in bringing to light crimes which have, for whatever reason, remained hidden."
