The leaders from different denominations are taking part in Prisons Week to think about all of those affected by crime in different ways.
Leaders are gathering at HMP Pentonville in North London to pray for those behind bars, as well as those working in the justice system and prisoner's families and victims of crime.
Tim Rosier, from Christian prison charity Reflex, told Premier's News Hour why they are praying.
He said: "Nobody is beyond hope and I think that by praying with people it shows that we recognise the power of the gospel; that nobody is behind hope.
"Prayer moves the heart of God and faith can move mountains, so this week I think we'll see people's lives transformed and our communities transformed too."
This theme this year is 'Lord have Mercy' and Christians are gathering across the country through services and events to pray together and unite communities.
Mr Rosier said: "Sin is not a measure of how bad we are, it's a measure of how good we're not - and whether we miss the mark but an inch or a mile, we've all missed the mark."
He went on: "Jesus encourages us as Christians to remember the prisoner.
"He implores us to clothe the naked, the feed those who are hungry, to house those who're homeless, and to remember those and visit those in prison."
Listen to Premier's Hannah Tooley speak to Tim Rosier here:
