What is the ruling on those who have cut ties for months or more, neither speaking to nor greeting one another?

This is a forbidden estrangement according to Islamic law, based on what is narrated in the Hadith (definition): "It is not permissible for a Muslim to abandon his brother for more than three [days]." Efforts must be made to reconcile them, for in the Quran: "No good is there in much of their private conversation, except for whoever enjoins charity or good or reconciliation between people." The virtue of the one who initiates the greeting should be clarified; if the other person responds, they both share in the reward, but if he does not respond, he incurs the sin, and the one who offered the greeting is absolved from the estrangement.