Is it always a sin to criticize someone on his back ?
We, as human beings, are both vulnerable and in the face of that vulnerability, dependent on seeking comfort in somebody. The best of us have learnt how to seek refuge in God and God alone; but most of us require that other human being too, to share our frustrations,anxieties and worries with. Some of these worries are inevitably linked towards the negative behavior of others, especially when it is persistent. Would you regard that as backbiting? Can the purpose of our talks be the defining line between backbiting and relaxation therapy?
The critical verse in this respect is this: “Allah doesn’t like loud negative mention except in case of the one who has been wronged.” (4:148) If an individual believes genuinely that he has been wronged and seeks to redress it through mentioning it to someone else, it will hopefully not come within the scope of an evil act. The onus of deciding whether the mentioning of one’s situation to the other comes within the scope of redressing an act of injustice is on the one who is seeking to get it redressed.
Probably the critical though subtle criterion one needs to apply is the question whether on negative mention of someone’s behaviour one is getting satisfaction through a feeling of avenging oneself, enjoying the possibility of the other person getting condemned, or whether one is simply stating facts to bring them to the attention of another person so as to get correct advice or simply the desired attention. If the latter is the case, then hopefully the negative mention would not qualify as a sin.
The next verse is however very relevant to the issue: “If you do an act of virtue, no matter openly or secretly, or ignore an evil (behaviour), (it would be a godly act), for God is forgiving (despite being) in full control.” (4: 149) There is a subtle message in the latter verse: If God forgives you despite having authority to punish, you should do likewise. And if you do likewise, He will forgive such sins of yours which otherwise had little chance of being forgiven.