What is the ruling of the Shari'ah regarding brothers treating their brother with hatred, hostility, and a lack of welcome, and what is the Shari'ah advice in this matter?

The Prophet, peace and blessings be upon him, forbade turning away from each other and abandoning each other among Muslims, especially among blood relatives, for severing ties of kinship is a major sin. It is incumbent to treat others with kindness and good character, overlook their faults, choose pleasant words, and for a Muslim to maintain ties with his kin, even if they cut him off.