In essence his human life in this world only to worship him, especially for Muslims. Where since the time of Prophet Muhammad SAW was ordered to fulfill the Pillars of Islam, Pillars of Islam is a standard of a person can be said fully religion Islam as for one of the contents of the pillars of Islam, humans are ordered to perform worship.
So that we can conclude that whoever does not pray Pray then he does not meet the pillars of Islam, if so then the person does not deserve to be called an Islamic. Not only that, even the person can be regarded as a person who has kufr against Allah SWT.
