question #3 Sahih Muslim 61, Book 1, Hadith 123 : What are the implications of labeling someone as an unbeliever or enemy of Allah without justification?

No person who claimed knowingly anyone else as his father besides (his own) committed nothing but infidelity, and he who made a claim of anything, which (in fact) did not belong to him, is not amongst us; he should make his abode in Fire, and he who labeled anyone with unbelief or called him the enemy of Allah, and he was in fact not so, it rebounded on him.