The article analyses the phenomenon of acedia which is often described as modern time evil by the thinkers of spiritual life and theologians whereas the Magisterium of the Catholic Church attributes this phenomenon to the seven capital vices. Acedia is analysed as one of temptations and difficulties of human life that deprives the person of hope. The article searches for expressions of acedia in biblical scriptures and analyses direct references to the phenomenon in the early monastic writings and works of other Church teachers. Multidimensional causes of acedia and its common characteristics that might help identify expressions of this spiritual illness in human life are also discussed.