Tābū WA āmanū: they repented AND BELIEVED. The verse names belief as part of the post-sin restoration. The sin shakes the faith; faith must be rebuilt with the tawbah.

There is a beautiful teaching from Ibn Taymiyyah on this verse. He writes that the believer's īmān increases with obedience and decreases with sin. Every sin is a small decrease. Every tawbah followed by belief is a renewal. The believer who does not pair his tawbah with re-belief is making half the repair. The Companions understood this. When ʿUmar would sin (even a small slip), he would not just say astaghfir Allāh; he would also say lā ilāha illā Allāh, renewing his fundamental declaration. The sin had loosened a thread; the re-shahādah re-tied it. So tonight, after your tawbah, take ten seconds to renew your belief. Say lā ilāha illā Allāh, Muḥammadun rasūl Allāh, slowly, with the full weight of meaning. Feel the heart re-anchor. The verse 7:153 closes the cluster with the practice: tawbah + belief renewal. The Lord, the verse says, is forgiving after that. Yā Allāh, when our sins shake our īmān, give us the courage to make tawbah AND to renew our belief in You. Restore what we damaged. Repair what we loosened. Bring us back to You whole, not in fragments. Āmīn.