Answer:
The five Islam pillars are very important because all the Islam teachings, principles, and morals are based on these five pillars. As the pillars are important for a building the pillars are important for the Islam religion.
Moreover, if you deny intentionally any of the five Islam pillars you are considered out of Islam faith and considered no longer Muslim or follower of Islam.
Refer to the related questions below for more information.
the 5 pillars of islam are what a muslim MUST do