5 But among the truths that shine out in the triple poem of Alighieri as in his other works We think that these things may serve as teaching for men of our times. That Christians should pay highest reverence to the Sacred Scripture and accept what it contains with perfect docility he proclaims when he says that "Though many are the writers of the Divine Word nevertheless there is but one Dictator, God, Who has deigned to show us His goodwill through the pens of many" ( Mon . III, 4). Glorious expression of a great truth. Again, when he says that "The Old and the New Testament, prescribed for eternity, as the Prophet says, contain 'spiritual teachings transcending human reason,' given 'by the Holy Ghost who by means of the Prophets and sacred writings, through Jesus Christ coeternal Son of God and through His disciples revealed the supernatural truth necessary for us"' ( Mon . III, 3, 16). And therefore regarding the life to come "It is assured by the true doctrine of Christ who is the Way, the Truth and the Life: the Way because by that way we advance without hindrance to the happiness of that immortality; the Truth because He is free from all error; the Light because He enlightens us in the darkness of ignorance of this world" ( Conv . II, 9). And no less reverence he pays to "those venerable Great Councils the presence of Christ in which no one of the faithful doubts"; and great is his esteem for "writings of the Doctors, Augustine and the others, and if any one doubt that they were aided by the Holy Ghost either he has not seen their fruits or if he has seen he has not tasted" ( Mon . III, 3).
Source: In Praeclara Summorum (Vatican.va)