Baptists, Methodists, United Reformists and Scottish Anglicans are urging Philip Hammond to undo a four year freeze on most working age benefits introduced in April when he updates MPs on taxation and spending plans.
The message from the Joint Public Issues Team (JPIT) comes amid a Bank of England report earlier this month which predicted inflation could reach five per cent next year if the base rate of interest remains unchanged.
Speaking about a scenerio where inflation rises to four per cent next year, policy advisor Paul Morrison from the (JPIT) told Premier: "That means [for] somebody whose benefits are frozen, they'll [affectively] have four per cent less money next year.
"This compounds itself [if inflation stays at four per cent the following year], so the year after, that will add again...
"This cut could go way out of control unless the Chancellor decides in the Autumn Statement to stop freezing benefits and to decide to, if he wants to do a cut, say how much it will be and back that."
The JPIT includes the Baptist Union of Great Britain, the Church of Scotland, the Methodist Church and the United Reformed Church.
Paul Morrison went on to say a decision to implement a four year freeze on the majority of working age benefits did not account for economic uncertainty caused by Brexit and "all sorts of other economic tribulations".
Rachel Lampard, Vice President of the Methodist Conference, said: "In January, when Parliament voted to freeze benefits, inflation was low, stable and predicted to remain low. Today the economic outlook is very different.
"Rising inflation will mean 7.5 million children will be hit by cuts harder and faster than was ever intended."
Philip Hammond is due to announce a two pence cut in the "taper rate" for Universal Credit - where welfare is withdrawn for every extra pound a low-paid worker earns above their work allowance.
He is expected to reduce the rate from 65 per cent to 63 per cent in a move the IPPR think-thank estimates will cost the Treasury £700 million per year by 2020/21.
Labour has warned to decision will still leave many low-income families worse off next year.
Rev Stephen Keyworth, Faith and Society Team Leader of the Baptist Union of Great Britain said: "If the benefit system is to do its job of supporting families through difficult times, there must be a link between the price of food and shelter and the value of benefits."