What is the ruling on persisting in sin, and does it have another meaning besides mockery, such as "weakness"? And what should one do who is unable to stop sinning despite repenting, and should he seek forgiveness during this period?

Seeking forgiveness with the tongue while persisting in disobedience and feeling no remorse is like mocking the Lord. The reasons for persisting in sin are numerous, including weakness of faith, lack of certainty, and the dominance of desires. A Muslim must repent immediately and not procrastinate; if they return to the sin, they must renew their repentance and not despair. Abandoning sin is not impossible and requires will, determination, and remembrance of God's greatness and His constant watchfulness. Allah Almighty has commanded us to repent.