Some Reasons Why Some Who Know the Truth Still Reject It
Ibn Taimiyyah, may Allāh have mercy on him, said:
A person might know that the truth is [found] with someone else; despite this, he outwardly denies that [truth] due to his envy for him, his wanting to be in a higher position above him, or [his having] desires in [his] soul.
Majmūʿ Al-Fatāwá, vol. 7, p. 191.
N.B.: Title mine (Trans.)