Seeing All Saints faced with a £92,000 bill for urgent work, he took swift and decisive action.
And this resulted in him making an epic run wearing a huge cardboard model of the church building.
The challenge netted more than £2,500 so far, but Jonathan hopes his efforts will inspire more people to make donations to the cause.
Jonathan, a churchwarden at All Saints, did the 19-mile run on Sunday, donning the 8ft by 12ft specially-made model for the second half of the route, for which he was joined by fellow warden, Ruth Holloway.
Vicar Rev Maureen Browell said: “This was a great idea visually but a nightmare to run in.
“Jonathan has been an absolute inspiration. When the church council discovered the need for essential roof repairs costing £92,000, he took decisive action and arranged the run in just five weeks.”
Jonathan, a former Royal Navy diver, had been helping to clear the guttering, believing it to be the reason for water getting into the Grade I-listed church.
However, it was soon discovered the stone gutters had collapsed, leading water to saturate the inner walls and causing roof timbers to develop dry rot. The damage also threatened to affect the listed organ beneath.
“His efforts have been hugely appreciated by his supporters and it’s hoped the total raised will encourage others to find innovative ways to raise the rest of the money needed for the repairs,” Rev Browell added.