"Did you wonder why this issue is raised every now and then?" Sheikh Saleh bin Humaid, who also heads the Saudi-appointed Shura (consultative) Council, asked at the Grand Mosque in Mecca, western Saudi Arabia.
He was referring to controversial remarks by Pope Benedict XVI last month.
The issue "was raised only because the hearts of observers among the adversaries are filled with resentment over the spread of this faith and its overcoming of all borders, barriers and blocks in all eras and under all circumstances," bin Humaid said.
Bin Humaid was delivering the feast sermon to throngs of worshippers led by King Abdullah and other Saudi dignitaries on the first day of Eid ul Fitr that marks the end of Ramadan. His remarks were reported by the official Saudi SPA news agency.
"Copies of the Holy Quran are a best-seller among non-Muslims in the world and the numbers of those converting to God's religion (Islam) are quickly multiplying" in Christian and other non-Muslim countries, bin Humaid said.
"Religious and political leaders there have warned against the victory of Islam and its expansion," he said.
Bin Humaid, who did not mention Western countries by name, cited what he said was a specialised study produced by "them" and which predicted that Islam would prevail.
The study "said that the future world order will be religious, and the Islamic order will prevail despite its current weakness because it (Islam) is the only religion that enjoys a comprehensive power", bin Humaid said.
This explains why "the symbols of Islam" are being abused and the Muslims' activities and charities are subjected to scrutiny and restrictions in non-Muslim countries, he said.
The head of the Roman Catholic Church offended Muslims when he quoted the medieval emperor who equated Islam with violence. The pontiff later said he regretted the offence his comment had caused, but did not explicitly apologise for or retract it.

Copyright AFP (Agence France-Presse), 2006