Michael Pulsford, 68, abused three boys and three girls while he was a Christian youth group leader between 1974 and 1989.
The victims, who were aged between 12 and 15, were abused in Wiltshire, Hampshire and the Isle of Wight.
Pulsford admitted 16 counts of indecent assault. He was sentenced to eight years and eight months in prison.
Southampton Crown Court heard Pulsford groomed children while he was viewed as a “pillar of the community” during summer camps, at his home and in his office.
His victims described Pulsford, of Corsham in Wiltshire, as “an evil manipulator” who had taken their “childhood innocence” by “abusing his position of trust”.
But police reopened the investigation in 2017 when another victim reported Pulsford for indecent assault.