The Christian leaders are particularly concerned about the Islam Defenders Front (FPI), an extremist group that has claimed responsibility for a number of attacks against Christians.
The FPI was founded in 1998 and has been described as an "urban thug organisation" by the International Crisis Group NGO.
In 2008, the group attacked some 200 Christians and moderate Muslims who were rallying for religious tolerance at the National Monument in Jakarta.
The group have also organised a number of mass demonstrations against Christian Governor of Jakarta Basuki 'Ahok' Tjahaja Purnama, who is on trial for blasphemy charges.
FPI leader Muhammad Sidieq Shahib, 51, is currently facing police investigation over eight hate speech and blasphemy complaints.
Christian leaders have said the FPI pose a "serious threat to national unity".