The Church of England is rallying members to support a global vigil taking place in the coming days to highlight the suffering of millions of Syrians.
Vigils are being organised in major cities around the world, including Beijing, Washington DC and London.
Coventry Cathedral will be hosting a #WithSyria vigil on Thursday at 6pm. A vigil will be held at the same time in London's Trafalgar Square featuring a light projection onto Nelson's Column.
In addition to the Church of England, the #WithSyria coalition includes Christian Aid, Amnesty International, War Child and Tearfund.
The vigils coincide with the third anniversary of the start of the Syrian conflict on Saturday.
The Church of England said it hoped the vigil would be the largest public mobilisation on Syria so far.
The Bishop of Coventry, Dr Christopher Cocksworth, made an impassioned plea to people to take part.
"The scenes of destruction and suffering from Syria point to an apocalyptic disaster and yet the massacre in Syria continues unchecked," he said.
"How many more harrowing scenes of exhausted families crossing the borders from Syria must we bear witness to before world leaders take the necessary steps to resolve this conflict?
"For how long must we hear the heartbreaking stories of hungry crying children from besieged cities in Syria before we secure unfettered humanitarian access to those most in need?
"We can remain silent no more. The world can ill-afford another anniversary for Syria marked by bloodshed."
The United Nations puts the number of Syrian refugees at over 2.5 million. Within Syria there are another 9.3 million people who need humanitarian assistance, some 6.5 million of them are internally displaced.
Dr Cocksworth continued: "This week the Church stands with others in shining a light in solidarity with the people of Syria and as a demonstration to our own government, and others, that they must intensify their efforts to end the bloodshed and to get aid to all those in need."
To find out where your nearest vigil is taking place visit http://www.with-syria.org/en