Why are the five pillars so important to Islam believers?

The Islamic faith has no worldwide leader and
a myriad of different interpretations. Quite apart from the most significant division into Sunni
and Shia Islam, there are various sub-groups, denominations, sects, and derived religions. This
means that there are around 1.8 billion people who identify as Muslim, and there is very little
on which they can all agree, except for the Five Pillars of Islam.

The first
pillar, Shahadah, articulates what it means to be a Muslim. It is the simplest profession of
faith of any major religion: There is no God but God, and Muhammad is his Prophet. This
articulates in a short, simple sentence what it means to be a Muslim. The second pillar, Salat,
gives structure to the day by setting out the times of prayer and the way in which prayer should
be conducted. The third pillar, Zakat, outlines the Muslim's social duties to help the poor. The
fourth and fifth, Sawm and Hajj, prescribe major religious observances: fasting and
pilgrimage.

Collectively, these five pillars set out the principal points
that make a Muslim a Muslim: the bare minimum one needs to know in order to accept and practice
the faith.