St Paul's Church, Grangetown, Cardiff Some churches such as St Paul's in Grangetown, Cardiff, face repair bills of up to £1m
The Church in Wales has to "reimagine" its purpose as it approaches its centenary, according to a bishop.
The first of six public meetings takes place in Carmarthen later on Tuesday as part of a wide-ranging review.
Bishop of Bangor Andrew John says the church needs to use its stock of buildings more creatively and adapt to better serve modern Wales.
"If all that we do is concentrate on a Sunday we're missing a trick or two," he said.
A review led by the former Bishop of Oxford, Lord Harries, is already under way into how the Church in Wales should restructure and reinvent itself in time for its centenary in 2020.
The Archbishop of Wales, Dr Barry Morgan, urged officials to be open to "significant change" when he launched the review in April.
Public meetings in the six dioceses in November and January will give worshippers and other interested parties the opportunity to share their views on the church's future direction.
A team of consultants will generate a plan for change based on responses received during the review.
Figures from the Church in Wales show that while membership had fallen by almost two thirds since numbers were first recorded in 1959, the number of churches has fallen by less than a quarter.