Ibn al-Qayyim (d. 751 AH) rahimahullāh mentions:

Beware, beware of two matters that have evil consequences.

The first of them: Rejection of the truth because it opposes your whims and desires. So you will be punished with the turning of your heart away (from guidance) and with you rejecting whatever comes to you from the truth. And you will not accept the truth unless it is evidently in accordance to your desires. Allāh, the Most High, mentions:

وَنُقَلِّبُ أَفْئِدَتَهُمْ وَأَبْصَارَهُمْ كَمَا لَمْ يُؤْمِنُوا بِهِ أَوَّلَ مَرَّةٍ

“And We shall turn their hearts and their eyes away (from guidance), just as they refused to believe in it (i.e. the revelation) the first time.”
[al-Anʿām, 6:110].

So Allāh punished them – because of their rejection of the truth the first time – by turning their hearts and their eyes away (from guidance).

The Second (Affair): al-Tahāwan (wilfully neglecting and disregarding) a command (in the religion) when its time has arrived. So if you wilfully disregard it (i.e. a command) then Allāh will impede you and prevent you from those things which Please Him and His Commands; as (a form of) punishment for you. Allāh, the Most High, mentions:

فَإِن رَّجَعَكَ اللَّهُ إِلَىٰ طَائِفَةٍ مِّنْهُمْ فَاسْتَأْذَنُوكَ لِلْخُرُوجِ فَقُل لَّن تَخْرُجُوا مَعِيَ أَبَدًا وَلَن تُقَاتِلُوا مَعِيَ عَدُوًّا ۖ إِنَّكُمْ رَضِيتُم بِالْقُعُودِ أَوَّلَ مَرَّةٍ فَاقْعُدُوا مَعَ الْخَالِفِينَ

“If Allāh brings you back to a party of them (the hypocrites), and they ask your permission to go out (to fight), say: ‘Never shall you go out with me, nor fight an enemy with me; you agreed to sit inactive on the first occasion, then you sit (now) with those who lag behind.’”
[Tawbah, 9:83].

So whoever is safe from these two great calamities and tribulations, then he will live comfortably with safety.

Translated by: Abū ʿAbdillāh Bilāl Hussayn al-Kashmirī
Reference: Badāiʾ al-Fawāʾid by Ibn al-Qayyim, (3/1128-1129), Dār ʿĀlam al-Fawāʾid edition.