What is the ruling on one who insults the Lord or the Messenger, and does he have a path to repentance?

Question:
Who distinguishes between insulting the Messenger (peace and blessings be upon him) and insulting the Lord ?

Answer:
I am not aware of any distinction; it is all a clear apostasy.
Q: Regarding the acceptance of repentance: the one who insults Allah, his repentance is accepted, but the one who insults the Messenger, his repentance is not accepted?
A: Some scholars distinguish; because insulting the Messenger is a right of a human being, whereas insulting Allah is a right of Allah, and Allah (Exalted and Majestic is He) forgives and pardons. This is the basis for the distinction, and Shaykh Taqi al-Din (may Allah have mercy on him) elaborated on the matter in *Al-Sa'ir al-Masul*.
Q: Is not insulting the Messenger also an insult to Allah?
A: No, insulting the Messenger entails disbelief. The most likely view—Allah knows best—is that if one comes repentant and remorseful, [it is accepted]; because shirk (associating partners with Allah) is the greatest insult, shirk with Allah and worshipping others is among the greatest insults. We ask Allah for safety. So if he comes repentant, praise be to Allah.