what is the main rule that all muslims must follow ?

just follow the holly quraan . Will take you to the right path

follow qur'an and sunna and the islamic rules do the five pillars of practice in islam and keep urself away from any prohibted things.

http://www.facebook.com/The0Islams0reality

`Aishah (May Allah be pleased with her) said: The conduct of the Prophet (PBUH) was entirely according to the Qur'an. [Muslim in a long Hadith].

Commentary: This Hadith shows that the life of the Prophet (PBUH) and all modes of his actions were on the pattern given in the Qur'an. In his life we can observe the perfection of obedience to all the commands of the Qur'an. In fact, he was a living example of the Qur'an.

Assalamualaikum.

Solat. solat . solat. because Solat is the main pillar.

Wassalam.

Balance in following all the rules. :)

Assalamoualaikoum..according to the quran,five pillars of islam...1.the shahada (Islamic creed) 2.daily prayers (salat) 3.almsgiving (zakāt) 4.fasting during Ramadan (sawm) 5.the pilgrimage to Mecca (hajj) at least once in a lifetime