Will all good deeds be useless if one trangresses the sacred limits of Allah in private according to this Hadith?

Question

I need help with this hadith of Sunan Ibn Majah 4245:

“I certainly know people of my nation who will come on the Day of Resurrection with good deeds like the mountains of Tihamah, but Allah will make them like scattered dust.” Thawban said: “O Messenger of Allah, describe them to us and tell us more, so that we will not become of them unknowingly.” He said: “They are your brothers and from your race, worshipping at night as you do, but they will be people who, when they are alone, transgress the sacred limits of Allah.”

Will the deeds be rendered useless ONLY when one doesn't repent and dies in that state? Are the deeds still valid as long as one doesn't die not repenting beforehand? 

Answer 1

First of all, I'd like to state that this is a Hasan (fair) hadith, meaning it is not Sahih (authentic) because its isnad (chain of narration) contains 1 or more narrators whose memory weren't considered good enough to make this hadith Sahih.

Allah's Mercy

Allah's Mercy is vast and promises mercy to the believers.

Quran 7:156

Ordain for us what is good in this life and the next. Indeed, we have turned to You ˹in repentance˺.” Allah replied, “I will inflict My torment on whoever I will. But My mercy encompasses everything. I will ordain mercy for those who shun evil, pay alms-tax, and believe in Our revelations.

In Islam, those who have a mustard seed of faith in their hearts will eventually go to heaven (because of Allah's mercy) and will not abide in hell forever if they were in hell in the first place.

Sahih Bukhari 6560

Narrated Abu Sa`id Al-Khudri: Allah's Messenger (ﷺ) said, "When the people of Paradise have entered Paradise, and the people of the Fire have entered the Fire, Allah will say. 'Take out (of the Fire) whoever has got faith equal to a mustard seed in his heart.' They will come out, and by that time they would have burnt and became like coal, and then they will be thrown into the river of Al-Hayyat (life) and they will spring up just as a seed grows on the bank of a rainwater stream." The Prophet (ﷺ) said, "Don't you see that the germinating seed comes out yellow and twisted?"

We have to believe and trust in the mercy of Allah. If a person dies as a believer even while in a state of sinning (May Allah protect us from that), their ultimate destination is Jannah even if they have to go to hell first.

The Infinitely Merciful and the Question of Hellfire

Dying in a State of Disbelief

But if a person dies in a state of disbelief (whether they were once believers or not), meaning committing a sin that takes them out of Islam such as believing in Shirk, then, unfortunately, all the good deeds they committed in this life will not benefit them in the here-after:

Quran 24:39

As for the disbelievers, their deeds are like a mirage in a desert, which the thirsty perceive as water, but when they approach it, they find it to be nothing. Instead, they find Allah there ˹in the Hereafter, ready˺ to settle their account. And Allah is swift in reckoning.

Do Non-Muslims Get Rewards For Doing Good Deeds?