What is the punishment for those who does not believe in fate or Taqdir?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

As for the belief in fate or predestination, this is one of the pillars of Imaan (faith), so whoever does not believe in fate and predestination has no faith. The Prophet said to Angel Jibreel (Gabriel) – when he asked him about Imaan (faith): “Iman is to believe in Allah, His Angels, His Books, His Messengers, The Last Day, and to believe in predestination whether it is good or bad.”

Allah knows best.