Muhammad ibn Yahya has narrated from in a marfu‘ manner from Amir al-Mu’minin Ali (a.s) who has said the following.
"If one would establish firmly in himself one good quality for me I will credit him for it and forgive his other shortcomings but I will not forgive him for his losing intelligence and religion because departing religion is departing peace and security. Thus, life with fear and insecurity is unpleasant. Loss of intelligence is loss of life. A person without intelligence can be compared with no other thing but the dead."