'Do not let yourself be blinded by the red carpet in Khartoum. The hands you will shake will be full of Christian blood,' the message said. It pleaded with the pontiff to 'help us lift the curtain of silence' - a curtain which Bishop Taban said hides widespread religious and ethnic persecution.
Bishop Taban and other Sudanese Christians view the Pope's visit to Sudan with both hope and fear. Ironically, so do Sudan's Islamic leaders. Of all the stops on the Pope's eight-day African tour, the last one today in Khartoum is the most controversial.
An international pariah condemned by the United Nations, the European Community and the United States for human rights violations, cold-shouldered by its Arab allies, Sudan has been looking forward to today. According to Gutbi al-Mehdi, the political director of Sudan's Foreign Ministry, the Pope will see 'the falsehood of reports and allegations that reach the Vatican'.
The Vatican is among those who accuse Khartoum's fundamentalist-dominated government of violating human rights by trying to impose Islamic law on the Christian and animist minority in the south of the country. This point was underlined yesterday by the Foreign Office Minister Douglas Hogg, who told the UN Commission on Human Rights in Geneva that in Sudan there is no freedom of religious expression and that the most fundamental of human rights are abused. The Vatican, aware of the dangers of giving the government unwarranted respectability, is promoting the trip as an expression of solidarity with southern Sudan's beleaguered population.
On Monday the pontiff told diplomats in neighbouring Uganda that conditions did not allow a full pastoral visit, but that in visiting the capital he wished to show support for 'peace and justice for all the Sudanese people and to comfort my brothers and sisters in the faith, so many of whom are affected by the conflict in the south'.
Sudan's long-running conflict is commonly seen to pit Muslim against non-Muslim and Arab against African in a war between the predominantly Muslim-Arab north and the black Christian-animist south. However, according to Mohammed Suliman, the deputy director of the Institute for African Alternatives in London, there is a growing economic element to the war that does not distinguish between Muslim and non-Muslim. The persecution of black Muslim Nuba tribesmen in south central Sudan, whose fertile lands are much-coveted, is a case in point.
Sudan's leaders are trying to give the lie to reports of repression and restrictive measures against the Christian church by talking of tolerance and a multi-faith society. The Catholic church has been supplied with scarce petrol for the visit; today's Mass will be broadcast live on television; missionaries expelled from the south have been told they can return. But the big question still, according to one Sudanese exile in London, is: 'What is going to happen after the Pope has gone?'