Islam is based on (the following)
To testify that none has the right to be worshipped
but Allah and Muhammad is Allah's Apostle.
To offer the (compulsory congregational) prayers
dutifully and perfectly.
To pay Zakat (i.e. obligatory charity) .
To perform Hajj. (i.e. Pilgrimage to Mecca)
To observe fast during the month of Ramadan.
Narrated Ibn 'Umar: