Actually the 30% christian community just refers to the maronite christians and does not take into account other christian groups including Greek orthodox
In reality the christian groups make up just over 50% of the population
Religion: Unlike most other Arab countries, Lebanon is characterized by great religious and cultural diversity. At the time of independence Christians formed a slight majority of the population, the largest single community (nearly 30% of the total) being the Maronite Christians, who mostly inhabited the north of Lebanon and the capital, Beirut. Other Christian groups included Greek Orthodox communities, Greek Catholics and Armenians. The Muslim groups were the Sunnis (living mainly in the coastal towns of Tyre, Sidon and Beirut), the Shi´as (a predominantly rural community in southern Lebanon and the northern Beka´a valley) and the much smaller Druzes, an ancient community in central Lebanon.
http://www.arab.de/arabinfo/lebanon.htm
What do you want to discuss about your posting? Maybe the fact that each section of the population gets that percentage of seats in parliment??