The scholars stated that one who kills a believer does not become a disbeliever, so what is the answer to the hadith: “Cursing a Muslim is open sinfulness, and fighting him is disbelief”?

Question:
May Allah reward you, Honorable Shaykh. This questioner says that the opinion of the majority and the opinion of Ibn 'Abbas (may Allah be pleased with them both) is that one who kills a believer does not become a disbeliever, so what is the answer to the hadith ?

Answer:
It is minor shirk (associating partners with Allah), minor shirk, based on the saying of the Messenger (peace and blessings be upon him) This is minor shirk. So disbelief is of two types: major shirk, which takes one out of the religion, and minor shirk, and this is the minor type. Yes. The other proofs indicate that one who kills a believer does not become a disbeliever, but rather commits a major sin. The Muslim, or the scholar and student of knowledge, must gather the evidence; he takes one proof and leaves the other. He must gather the evidence, compare them, and see. This is something that is only possible for scholars; not everyone issues fatwas and not everyone judges people. This is referred back to the people of knowledge who know how to reconcile the evidence and how to derive rulings.
The one who does not have the qualification should fear Allah and not enter into these matters. Yes.