Imām Ibn Qayyim Al-Jawziyyah (رحمه الله) said:
‘And the Religion revolves around 4 principles; i) Love, ii) Hate; and which result in either, iii) Action or iv) Abandonment.
And so whomsoever loves, hates, acts or abandons for the sake of Allāh, then they have perfected their Īmān. As in, if they love; they love for Allāh, if they hate; they hate for Allāh, if they do an action; they do it for Allāh and if they abandon something; they abandon it for Allāh.
And īmān will decrease in direct correlation to its defficieny in these 4 principles.”
Ar-Rūh “The Soul”, Publisher: Al-Maktab Al-Islāmī – page 490.