The growth of Islam Religion today
Based on the percentages published in the 2003 CIA factbook, Islam is the second largest religion in the world. According to the World Network of Religious Futurists the U.S. Center for World Mission and the controversial Samuel Huntington, Islam is growing faster numerically than any other religion. It is a matter of great controversy whether this is due in large part to the higher birth rates in many Islamic countries, or whether a high conversion rate may also be a factor.
The Muslim population today comprises over 1.3 billion people; estimates of Islam by country based on US State Departement figures yield a total of 1.48 billion, 22.82% of the world's population. However, only 18% of Muslims live in the Arab world; a fifth is found in Sub-Saharan Africa, about 30% in the Indian subcontinental region of Pakistan, India and Bangladesh, and the world's largest single Muslim community (within the bounds of one nation) is in Indonesia. There are also significant Muslim populations in China, Europe (especially in the Mediterranean countries), Central Asia, and Russia. There are approximately 5 million Muslims in North America. The world population is growing at about 1.10% per year, but the percentage of Muslim population is increasing by 1.4% per year, mostly due to higher birth rate of African and Asian countries. Birth rates in many Muslim countries have begun to decline, although more slowly than in other nations, which also may be a factor.
Denominations of Islam
There are a number of Islamic religious denominations, each of which has significant theological and legal differences from each other. The major branches are Sunni and Shi'a, with Sufism often considered as an extension of either Sunni or Shi'a thought. All denominations, however, follow the five pillars of Islam and believe in the six pillars of faith (mentioned earlier).
The Sunni sect of Islam comprises the majority of all Muslims (about 90%). It is broken into four similar schools of thought (madhhabs) which interpret specific pieces of Islamic practice. They are named after their founders Maliki, Shafi'i, Hanafi, and Hanbali. Each school of thought differs slightly on fiqh (thoughts on how to practise Islam) although all accept the fundamentals contained within the Holy Quran.
Shi'a Islam comprises most of the Muslims that are not counted among the Sunni. The Shi'a consist of one major school of thought known as the Jafaryia or the "Twelvers", and a few minor schools of thought, as the "Seveners" or the "Fivers" referring to the number of infallible leaders they recognise after the death of Muhammad. The term Shi'a is usually taken to be synonymous with the Jafaryia/Twelvers.
While some consider the Islamic mysticism called Sufism to constitute a separate branch, most Sufis can easily be considered Sunni or Shi'a. Sufism is the hardest to understand by non-practitioners because on first sight it seems that sufis are either of Shi'a or Sunni denomination, but it is true that some sects of Sufism can be categorised as both Sunni and Shi'a whilst others are not from either denomination. The distinction here is because the schools of thought (madhhabs) are regarding "legal" aspects of Islam, the "dos" and "don'ts", whereas Sufism deals more with perfecting the aspect of sincerity of faith, and fighting one's own ego. Other people may call themselves Sufis who may be perceived as having left Islam (or never followed Islam). There are also some very large groups or sects of Sufism that are not easily categorised as either Sunni or Shi'a, such as the Bektashi or those that can be categorised as both at the same time, like the Barelwi. Sufism is found more or less across the Islamic world, though bearing distinctive regional variations, from Senegal to Indonesia.
According to Shaikh Mahmood Shaltoot, Head of the al-Azhar University in the middle part of the 20th Century, the Ja'fari school of thought, which is also known as "al-Shi'a al- Imamiyyah al-Ithna Ashariyyah" (i.e., The Twelver Imami Shi'ites) is a school of thought that is religiously correct to follow in worship as are other Sunni schools of thought. This position was not generally accepted by mainstream Sunni scholarship, and al-Azhar itself distanced itself from this position.