Imam Khomeini defended Islam and spirituality

Imam Khomeini defended divine region of Islam and spiritual values by writing his famous work known as Kashfol-Asrar at sensitive juncture of history

Imam Khomeini in his book Kashfol-Asrar defended Islam, spirituality

Imam Khomeini in his famous book entitled Kashfol-Asrar had strongly defended Islam and spirituality.

What is the main subject of Imam Khomeini's significant book known as Kashfol-Asrar?