South Sudanese follow mostly Christianity

Unlike the predominantly Muslim population of Sudan, the South Sudanese follow mostly Christianity and traditional religions. Roman Catholic missionaries began work in Sudan in 1842; there are now some 2,009,374 South Sudanese practicing Roman Catholicism. The majority of Christians in South Sudan are adherents of either the Roman Catholic or Anglican churches (represented by the Episcopal Church of the Sudan) but there are several other small denominations represented. Speaking at Saint Theresa Cathedral in Juba, South Sudanese President Salva Kiir Mayardit, a Roman Catholic, stated that South Sudan would be a nation which respects the freedom of religion.
the population of South Sudan (8,260,490); demographic data includes South Sudan (July 2012 est.)