According to some of the Imaams of the Salaf like Ibnul Qayyim, may Allaah have mercy upon him the Pillars of Kufr are four: Al-Kibr, wal-Hasad, wal-Ghadab wash-Shahwah:

1) Al-Kibr (Arrogant Pride) is that which restricts the individual from submitting to Allaah and His obedience!

2) Al-Hasad (Envy/Jealously) is that which restricts him from accepting naseehah (good advice) and submitting to it!

3) Al-Ghadab (Anger) is that which prevents him from being just and impartial!

4) Ash-Shahwah (Desire and Carnal Appetite) is that which restricts him from being devoted to worship!