What does the word sincerity mean in the term of sincere repentance?
In the Name of Allah, the Most Merciful and Compassionate
Sincerity is one’s repentance refers to one’s remorse and resolve never to repeat such sin.
If one turns to Allah Most High in repentance but doesn’t truly have remorse for their sin or plans to repeat the sin – their repentance is incomplete.
[Ghazali, Ihya ‘Ulum al-Din]
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani