Palestine is today perhaps the most homogeneous society in the Middle East in matters of religion, being the only country with close to 100% of its population belonging to Sunni Islam.
1) Illegal settlers with Israeli passports.
Things were different earlier, when Judaism, Christianity and Druze religion were strong elements. Hardship over decades through the 20th century, the division into two separate entities, alongside great intolerance among Palestinian Muslims are the main factors leading to the present uniformity.
Palestinian Christians formed sizeable communities up until recently, but their number is now less than 1%.
Syncretism of Christianity and Islam
Reports of 19th century visitors to Palestine, tells about how Islam, Christianity and local cults had amalgamated into a unique religous structure, in which people considered themselves Muslims or Christians only depending on tribal identity, without actually being able to tell Christianity and Islam apart in matters of cult and concepts.
The main dimension of this religion was the veneration of shrines and sites of holy men and women, and the main festival was the Thursday of the Dead.
This development could happen only in an environment where there was great demise of political power, and no centralized religious leadership. Palestine at this time was thinly populated and too poor to be of much interest to its formal lords of the Ottoman Empire.
From early 20th century, religious education according to formal religion was spread, and the Muslim/Christian syncretism was gradually, yet quickly lost.
Most people in the occupied territories belong to Sunni Islam, and are reportedly conservative. Jerusalem is considered the main site of Palestinian Islam, with the al-Aqsa Mosque, but using this site for worship involves many challenges. Palestinians living in the freed territories have to go through a lot of formalities, before they are let into Jerusalem, and casual visits are consequently prevented.
Islam in Palestine is today practiced with few dimensions of popular religion. In recent decades, a radicalization has taken place in the country, allowing an Islamist interpretation of the religion to replace a more informal and tolerant understanding of religion and society.
Christianity is the religion of 6% of all Palestinians, in all countries. In the autonomous regions that generally are called Palestine, however, their number is radically lower, only 0.6%. Large groups of Christians have left their homelands, facing hardship from the Muslim majority, in particular from Islamists. In 1922, Christians represented 9.5% of the total Palestinian population.
Of the Palestinian Christians, most live on West Bank, only 2,000 Christians live on the Gaza Strip. About 15,000 in the Ramallah district, 8,000 in the Bethlehem district. In both areas, Christians formed the majority until the 1950's.
On the territory that is internationally considered Palestinian territory, Jewish settlers form communities of about 400,000. All these settlers are all considered Israeli citizens.
There are Jews that oppose the state of Israel, who call themselves Palestinian Jews. This is in particular the case for Neturei Karta; still these are all Israeli citizens and counted as part of the Israeli demography.