Ruling on not regarding a disbeliever as a Kafir

Q 2: We would like to know what the ruling is on a person who does not regard someone who is a disbeliever as a Kafir (disbeliever).

A: It is obligatory to believe in the Kufr (disbelief) of anyone who is confirmed to be a Kafir. The ruler is the one who should apply the Had (the prescribed penalty) for apostasy if they do not perform Tawbah (repentance). Anyone who does not regard someone as a Kafir whose Kufr has been confirmed, is also deemed as a Kafir, unless they have grounds for doubting the Kufr, in which case they must reveal this.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.