Such a person is an imbecile. Allah told us not to commit kufr. There are
those who commit kufr!
Likewise, Allah has asked us not to divide. It’s not mentioned in the Qur’an that we won’t be divided. Division and differences among this umrah is inevitable to which history bears witness and so do the texts of the sunnah of our Prophet salla Allahu aliaihi wa sallam.
Whoever rejects the authentic hadiths of the prophet salla Allahu aliaihi wa sallam is a disbeliever as Allah said that he (prophet) does not speak of his own desire.
Kindly refer to the following link(s):
https://islamqa.info/en/115125