What are the major sins in Islam?

(Kaba'ir) are the major sins. According to the correct opinion, major sins have no limits by which they can be identified by the servants of Allah; otherwise, people may commit minor sins and deem them lawful. Allah concealed the limits of major sins so that His servants may strive to refrain from what is prohibited to avoid committing major sins. Likewise, Allah has concealed the timings of al-Salat al-wasta [mid-day prayer], laylat al-Qadr [the Night of Power] and the time of responding to supplications.