The Bishop of Rochester, Rt Revd James Langstaff, will take part in a 'sleep out' at Bromley Parish Church in south east London next Saturday.
It's part of events to mark Homeless Sunday which takes place on January 18.
Bishop James is the chairman of Housing Justice which is leading the campaign.
A number of churches and denominations are taking part in events as well as charities.
The Bishop said: "Homeless Sunday is a valuable annual opportunity for the churches to think, pray and respond to the needs of homeless people.
"As chair of Housing Justice, I am very pleased to commend this very important opportunity and trust that the support materials offered will prove useful to everyone concerned with housing justice for all."
Alison Gelder, director of Housing Justice, said: "Churches are joining together to show concern for homeless people, challenge the causes of homelessness and celebrate their work in tackling the problems against the backdrop of the alarming rise in the numbers of homeless people, especially those sleeping on the streets.
"Last year's annual street count by the Department for Communities and Local Government showed that, for London alone, numbers had gone up from 415 to 543, an increase of 31%."