How can a Muslim escape divine punishment that wipes out years of worship, and how is divine forgiveness manifested in this situation?

The methodology of the Sunnis (Ahl al-Sunnah wa al-Jama'ah) regarding the texts of promise and warning is based on the principle that the texts of promise are a grace from Allah, and He does not break His promise. As for the texts of warning concerning a disobedient believer, these fall under His will. Good deeds are not nullified by sins, except for polytheism (shirk). Other sins may nullify some good deeds, but not all of them, contrary to the view of the Mu'tazilah and the Khawarij. There is no authentic hadith proving the existence of sins that nullify deeds for a specific number of years, even if some narrations from the Salaf mention this. Allah's mercy precedes His wrath, and a servant must be wary of deeds that nullify good actions, hasten to repentance, and increase in good deeds.