More than 700 people attended a special service to remember the former senior pastor at Gold Hill Baptist Church, and more watched from an online live webcast all around the world.
He had been the senior pastor at the Buckinghamshire church from 1968 to 1994 and a former President of Youth for Christ.
He passed away aged 84 on Tuesday, surrounded by his family.
Fiona Castle, widow of entertainer Roy Castle, told Premier his message was powerful.
She said: "I think what I noticed about Jim was his message, when he would stand up, whatever age he was he became so powerful.
"He was really Holy Spirit inspired every time he stood up to speak, so I don't think age made any difference to him."
Ms Castle went on: "I've been at Gold Hill now for 39 years, and I'd only just become a Christian when we moved.
"We just benefitted so much from Jim's teaching, I don't think I'd ever be able to thank him enough for what he taught we over the years, he's brilliant."
Stephen Gaukroger, pastor at Gold Hill from 1996 to 2008, and past Baptist Union President told Premier that he had a passion for boxing.
"He was a big fan of boxing, and it's really hard to believe that because Jim was the quietest, gentlest person on the planet.
"But he loved boxing!
"If you talked to him about boxing he knew all the fighters, talked with massive energy about it, and we laughed a lot around our dining room table."