Rev Steve Morris, who started Memory Cafe for those who are elderly, lonely and suffering from dementia, said it won't be a hard task.
He told Premier News Hour: "I bet you that every single person from a church, if you knocked on each door beside you, five on each side, you would find at least one person who is so lonely they wish they could die.
"As a church, we've got all kinds of missions and ministries we want to do, this is the closest at hand. As Christians and churches, we really can do something about it."
Rev Morris presented the challenge after a new study found elderly care home residents have as little as two minutes of social interaction per day.
The research - which was led by the University of Exeter, King's College London and Oxford Health NHS Foundation Trust - trained key care home staff to deliver person-centred care, such as talking to residents about their interests.
When combined with just one hour a week of social interaction, the programme improved quality of life and reduced agitation and aggression in people with dementia.
Rev Morris said the study's findings are not surprising.
"We have people coming to our Memory Café when we started it and they would say they literally had weeks without speaking to another human being. So I'm not surprised that a small amount of interaction makes a huge amount of difference."
The trial involved more than 800 people with dementia across 69 care homes in south London, north London and Buckinghamshire.
Two "care staff champions" at each home were trained over four day-long sessions, to take simple measures that involve talking to residents about their interests and decisions around their own care.
Importantly, the approach also saved money compared to standard care. Researchers said the next key challenge is to roll out the programme to the 28,000 care homes in the UK to benefit the lives of the 300,000 people with dementia living in these facilities.
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