Faulting others for what they have repented from can reflect the sin on oneself.
Benefitting from Being Happy with what Allah has Provided
It is reported that Al-Ḥasan Al-Baṣrī – Allāh have mercy on him – said:
Whoever is happy (satisfied) with what Allāh has apportioned for him, it will suffice him and Allāh will bless it for him, but whoever is not satisfied, then [what is apportioned for him] will not suffice him and it will not be blessed.
Ibn Abī Al-Dunyā, Kitāb Al-Riḍā ʿan Allāh bi Qaḍāʾihi article 95.
Also read
Related sayings.
Finding faults with others whilst not taking care of oneself is a sign of defective iman.
The believer is consistent, whereas the munafiq is a chameleon.