“The blood of a Muslim who testifies that ‘there is no god but Allah and that I am Allah’s Messenger’ may not be lawfully shed but for one of three reasons: a married man who commits adultery; a life for a life; and one who turns away from his religion and abandons the community.” [Sahih Al-Bukhari and Sahih Muslim]
Answer
The meaning of the Hadith is as stated.
The life of a Muslim is sacred. It is prohibited to take the life of another Muslim without any one of the three reasons stipulated in the Hadith quoted by you.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai