What is the ruling on denying one of the Fundamentals of Faith?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

Whoever denies one of the fundamentals of Faith is a disbeliever; we seek refuge with Allaah The Almighty from this act.

Allaah The Almighty Says (what means):

•        {O you who have believed, believe in Allaah and His Messenger and the Book that He sent down upon His Messenger and the Scripture which He sent down before. And whoever disbelieves in Allaah , His angels, His books, His messengers, and the Last Day has certainly gone far astray.} [Quran 4:136]

•        {Indeed, those who disbelieve in Allaah and His messengers and wish to discriminate between Allaah and His messengers and say, "We believe in some and disbelieve in others," and wish to adopt a way in between -Those are the disbelievers, truly.} [Quran 4: 150-151]

On the authority of ‘Umar ibn Al-Khattaab the Prophet, sallallaahu ‘alayhi wa sallam, said that Faith is to believe in Allaah, His Angels, His Books, His Messengers, the Last Day, and Fate whether good or bad. [Muslim]

In another Hadeeth (narration), on the authority of ‘Abd Allaah ibn ‘Amr the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said that one is not considered a true believer unless he believes in Fate; whether it is good or bad. [Ahmad; At-Tirmithi (Al-Arnaa’oot; Al-Albaani: Saheeh)]

On the authority of Zayd ibn Thaabit the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said that if a person spends in the way of Allaah The Almighty as much gold as the mountain of Uhud, He does not accept it from him until he believes in Fate and knows that everything happens to him according to the Fate of Allaah The Almighty. If he dies believing in anything other than this, he will enter Hell. [Ahmad; Abu Daawood (Al-Albaani: Saheeh)] 

Allaah Knows best.