The question dealed in the book is: what is happening when a Gospel passage is being read during the Mass? To answer this, we start from the celebration itself, that is to say its current and past development in the four Western liturgies three of which are still in force, the fourth is being closely linked: the Roman liturgy Ambrosian liturgy , Mozarabic liturgy and Gallican liturgy. We also seek the answer by examining the origins of the liturgical elements and their historical development and the explanations contained in the liturgical books.
Finalment we examine the general character of the proclamation of the gospel of a liturgical point of view, by inquiring into the origin of the solemn procession in the Liturgy of the Word, and we outline some ideas of theological interpretation from the liturgy.