The Churches Mutual Credit Union (CMCU), which offers not-for-profit financial services to several of the UK's major churches, was speaking after new figures revealed one in three working families could not afford to pay their rent or mortgage for more than a month if they lost their job.
The charity Shelter found three million working families in all could be just one pay cheque away from losing their home.
The figures come from a July 2016 poll of 8,381 adults which included 1,581 working families with children.
A third of families said they were unable to cover their housing costs for more than one month, while 23% of working families said they would be unable to pay their housing costs at all.
An increase in housing costs, currently unmatched by the rise in wages, is being blamed for the situation - though others have said some families are simply not saving properly.
Speaking on Premier's News Hour, Hilary Sams, from the CMCU, said: "I really know how hard it is for people to put money away for a rainy day, so I am not surprised.
"You've got the growing needs of your family, you want to be able to give some money to your church and give money to people in need as well, but sometimes you need to really cost that out.
"Sometimes there's a great shame put on Christians if they can't manage their money well - that shouldn't be the case.
"The Church does have a responsibility. The Church is a voice in this country to say that people should be dealt with fairly - to be there for people in their hour of need."
A Government spokesman said: "We are introducing the National Living Wage, increasing the personal tax allowance and giving the next generation choice and flexibility in their savings, including the Help to Save scheme for people on low incomes.
"We are continuing to spend around £90 billion a year on working age benefits to ensure a strong safety net for the most vulnerable.
"And for those who do fall on difficult times, there are strong protections in place to guard against the threat of homelessness, and ensure we don't return to the bad old days when homelessness in England was nearly double what it is today."
Listen to Premier's Alex Williams speaking to Hilary Sams on the News Hour:
