Praise be to Allah.
It is established among the majority of scholars that Allah, the Exalted, accepts sincere repentance from some sins without requiring repentance from others. For example, when repenting from false testimony, the witness is not required to repent from every other sin and disobedience he has committed. The Mercy of Allah is vast. He accepts repentance from His servants and rewards good with good, even if it is the weight of an atom. He does not waste the reward of one who does good due to a single bad deed.
Imam An-Nawawi (may Allah have mercy on him) said: "Repentance from one sin is valid, even if one persists in another sin. If one makes a sincere repentance fulfilling its conditions, then returns to that sin, the second sin is recorded against him, but his repentance is not invalidated. This is the doctrine of Ahl As-Sunnah..." (End quote from Sharh An-Nawawi `ala Muslim, 17/59).
Ibn Al-Qayyim (may Allah have mercy on him) said: "The core question is whether repentance can be partial, like disobedience, so that one can be repentant from one aspect but not another, similar to faith and Islam? The more correct view is that it can be partial. Just as repentance varies in its quality, it also varies in its quantity. If a servant performs one obligation but leaves another, he deserves punishment for what he left but not for what he did. Similarly, if he repents from one sin while persisting in another, because repentance is obligatory for both sins, he has fulfilled one obligation and left another. What he left does not invalidate what he did. This is like someone who leaves pilgrimage (Hajj) but performs prayer, fasting, and charitable giving (Zakat)..."
Then after some discussion and debate about the issue, he said: "My view on this matter is that repentance is not valid from one sin while persisting in another of its kind."
As for repentance from a sin while committing another that has no connection to it and is not of its kind: this is valid. For example, if one repents from Riba (interest/usury) but does not repent from drinking alcohol, then his repentance from Riba is valid. However, if one repents from Riba Al-Fadl but continues to engage in Riba An-Nasi'ah, or vice versa, or repents from taking hashish while continuing to drink alcohol, or vice versa: this repentance is not valid. This is similar to someone who repents from adultery with one woman while continuing to commit adultery with another, showing no repentance from the act itself, or someone who repents from drinking intoxicating grape juice while continuing to consume other intoxicating beverages. In reality, such a person has not truly repented from the sin but has merely shifted from one form of it to another, unlike someone who moves from one sin to a completely different category of sin. (End quote from Madarij As-Salikin, 1/284-285). Please see: (Al-Adab Ash-Shar`iyyah by Ibn Muflih (may Allah have mercy on him), 1/56-58; Mukhtasar Al-Fatawa Al-Misriyyah, 137; Majmu` Al-Fatawa, 10/23)
Therefore, Allah, the Exalted, accepts righteous deeds and repentance from sins, even if their doer is involved in boycotting his brother. The righteous deed is one matter, while the sin of boycotting is another. There is no interdependent relationship between them. The righteous deed does not require the removal of rancor between brothers to be accepted. There is absolutely no evidence that this rancor nullifies the servant's righteous deed. This is not what is meant in the noble Hadith: "The gates of Paradise are not opened but on two days, Monday and Thursday, and then every servant (of Allah) is granted pardon who does not associate anything with Allah except the person in whose (heart) there is rancour against his brother. And it would be said: Look towards both of them until there is reconciliation; look toward both of them until there is reconciliation; look towards both of them until there is reconciliation" (Narrated by Muslim, 2565).
If we understood it this way, we would be taking a wrong path that leads to closing the door of repentance and making servants despair of mercy. It would also lead to violating the sanctity of cursing and expulsion from mercy under the pretext of the sin of rancor, just as this sanctity was violated before in the name of declaring others as disbelievers (takfir) and misguided ones.
Rather, what appears to be the meaning of the noble Hadith is that the only sins not forgiven due to ,continuing rancor are the acts of rancor themselves that exist between those who boycott each other. Allah the Exalted, does not bestow forgiveness upon those who harbor rancor for this particular sin unless they repent from it and return to their previous state of brotherhood. In this mutual animosity and severing of ties, there are two sins: one relating to the Right of Allah, the Glorified, and another relating to the right of the person. If they reconcile and forgive each other, Allah will forgive them for what relates to His right as well. However, if they do not reconcile and do not forgive each other, He will not forgive them - neither for violating the person's right nor for violating the right of Allah, the Mighty and Majestic.
As for other sins between a person and their Lord, these are not connected to mutual animosity, and this noble Hadith did not address them.
Ibn `Abd Al-Barr (may Allah have mercy on him) says in (Al-Istidhkar, 26/159): "This shows the gravity of the sin of abandonment, enmity, and rancor against the people of faith. These are the people whom others trust with their lives, wealth, and honor. They are those who believe in Allah's promise and warning, and who avoid major sins and immoral acts. The Muslim servant is one who possesses these qualities and from whose tongue and hand Muslims are safe. It is not permissible for anyone to abandon or hate such people. Rather, loving them is part of religion, and maintaining alliance with them increases one's faith and certainty."
This Hadith provides evidence that when the sins between the servants of Allah are mutually forgiven, whether through mutual pardoning or releasing each other from their obligations, Allah - the Mighty and Majestic - drops His accountability for these sins. This is based on the Prophet's statement (peace and blessings of Allah be upon him) in this Hadith: "until they reconcile". Therefore, when they reconcile with each other, they are forgiven. (End quote). Please see: (At-Tamhid lima fi Al-Muwatta' min Al-Ma`ani wal-Asanid, 21/263)
Al-Qadi Ibn Al-`Arabi (may Allah have mercy on him) said: "The scholars among us stated: This Hadith proves that when servants of Allah mutually forgive and pardon each other's transgressions, or when some release others from what they owe them, Allah's claim against them is dropped. This is evidenced by his statement in this Hadith: 'Until they reconcile', and when they reconcile, they are forgiven." (End quote from Al-Masalik fi Sharh Muwatta' Malik, 7/279)
In conclusion: One who harbors ill feelings or disputes with his brother without legitimate reason will not be forgiven for the sin of discord until he reconciles with him. This is because it falls under the rights of people, which are only forgiven through mutual pardon. As for his other sins: sincere repentance or the Mercy of the Most Merciful will forgive them, even if he is in dispute with his brother. However, he should fear being deprived of complete forgiveness or not being guided to sincere repentance. The one who harbors ill feelings should fear for his own well-being. He should hasten to make reconciliation between people. Please see question number 98636.
And Allah knows best.
