Is avoiding mingling or prolonged conversation with a sister in Islam, while offering greetings and trying to be courteous in conversation with her, yet harboring a heartfelt dislike for her, considered a sin?

A Muslim must not harbor hatred or resentment towards his Muslim brother, for Allah Almighty says: (And do not put into our hearts [any] resentment toward those who have believed), and for the Prophet, peace and blessings be upon him, saying: (Do not hate one another, do not envy one another, do not turn away from one another, and be, O servants of Allah, brothers).

If the affection for someone is not at the level of close friendship, while fulfilling their religious rights, and this is not out of abandonment, then it is excused, for the Prophet, peace and blessings be upon him, said: (Souls are like conscripted soldiers; those whom they recognize, they get along with, and those whom they do not recognize, they differ with). This indicates the similarity of natures in good and evil, so souls harmonize if their natures agree and differ if they disagree.