If someone works productively for twenty years for an employer but then kills the employers’ child, all of those years of service will be worthless.
A bomb that destroys a building will destroy all of the labour and effort that went to building it in one instant.
Consuming one spoon of poison will mean the care and caution taken to consume only hygienic food will be destroyed.
A moment’s snooze while driving means the car will veer off the road.
A single moment in which a knife pierces an eye, will lead to years of blindness.
Yes, sins are also of that nature, in which a single sin can wipe out an entire lifetime of good work, like fire that burns a beautiful jungle down to ash. Like the Qur’an states:
“Their works have failed.”1
Of course, countering that are Ayahs that state
وَمَن يُؤْمِن بِاللَّـهِ وَيَعْمَلْ صَالِحًا يُكَفِّرْ عَنْهُ سَيِّئَاتِهِ
“And whosoever believes in God, and does a righteous deed, God will cover from him his evil deeds.”2
That would be like the employee that for years performed badly, yet if he springs into action in the moment of need and saves the child of his employer who fell into a swimming pool, will wipe out all of the employees’ bad behavior and shortcomings of his labor at work.
Likewise, the Qur’an states:
وَأَقِمِ الصَّلَاةَ طَرَفَيِ النَّهَارِ وَزُلَفًا مِّنَ اللَّيْلِ ۚ إِنَّ الْحَسَنَاتِ يُذْهِبْنَ السَّيِّئَاتِ
“And perform the prayer at the two ends of the day and night of the night; surely the good deeds will drive away the evil deeds.”3