Christian disability charity Livability has been putting this very question to people attending this year's Christian Resources Exhibition in Esher, Surrey.
Dementia currently affects around 800,000 in the UK, with that figure expected to rise to a million by 2020.
Livability is running a Dementia Friendly Church campaign to help change the lack of engagement with dementia.
The findings from its informal poll during the Christian Resources Exhibition lend weight to the need for such a campaign.
Charity representatives found that while 95% of the people they spoke to during the week knew someone affected by dementia, less than a third attended churches with activities engaging with people with dementia.
As part of the campaign, the charity is looking for churches with good examples of engagement with dementia.
Livability hopes to resource churches in better meeting the challenge of dementia and providing safe, loving spaces for people with the condition.
Livability's Mat Ray said: "Our snap survey shows that although dementia is an issue that affect so many of us, there are not really the resources in place to offer support within churches.
"Livability wants to change this and resource local churches so that they can be places of inclusion and participation for those touched by the condition."