In the celebration of the Mass, two parts are clearly distinguished. The first is called the liturgy of the Word and the second the Eucharistic liturgy. In the first part a passage from the Gospel is read, preceded by one or two readings taken from other writings of the Old or New Testament and a psalm. 
In the second part, the celebration focuses on the preparation of the bread and wine, which become the Body and Blood of Christ in the context of a great prayer of thanksgiving that the presiding priest raises to God. This second part leads to the rite of communion, during which those who are able to receive the sacrament receive the Body of Christ. Today we will focus on the first of these two parts.
These books have a special quality. They are books originally written in human languages, by human authors, according to the way of writing of each time and place. The books of the Old Testament are written mostly in Hebrew, several in Greek and a few in Aramaic. The books of the New Testament were written in Greek. Their authors were people of faith, members of the Jewish community those of the Old Testament, members of the Church those of the New Testament. But those authors produced something greater than what they themselves could do by their own resources. God appropriated, by the action of the Holy Spirit, the writing ability and skill of these men, so that what they produced was the human word, certainly, but also, and at the same time, the Word of God. That action of God on the authors of the books of the Bible is called “inspiration”. The books are inspired by the Holy Spirit.
The Word of God, of course, is first of all the Son of God. In the beginning there was already he who is the Word, and he who is the Word was with God and was God, says the evangelist John at the beginning of his Gospel. But that Word became flesh. Jesus Christ made man is the Word of God in human existence. But that Word of God already spoke of old, through the work of the Holy Spirit, in the prophets. On different occasions and in many ways God spoke in the past to our fathers through the prophets. Now, in these times, he has spoken to us through his Son, teaches the letter to the Hebrews in its first sentence. The Word of God, who is the Son of God, in a certain way also becomes a human word in order to transmit God’s message to us, the Word of God made language. By means of inspiration, the sacred authors have produced the books of the Bible, which transmit to us the Word of God. Of all these books, the Gospels are the most important, for in them the Word of God himself, Jesus Christ, speaks. For this reason, their reading is surrounded by rites that emphasize their importance and sanctity.
Where does the custom of worshipping God by reading and listening to the books of the Bible come from? It is a custom that the Christian Church inherited from the Jewish synagogue. Today’s first reading, taken from the book of Nehemiah, narrated how it was the first time that the Law of God was read in a worship context. Ezra, the priest, read, with the help of translators, from a platform the books of the Law, probably all or some passages from the first five books of the Old Testament. He read in Hebrew and the translators proclaimed it in Aramaic for the people to understand. People listened and put the Word of God in their hearts. But the Gospel tells us how Jesus himself read, in the synagogue of his town, Nazareth, a passage from the book of the prophet Isaiah and explained that this passage was fulfilled in his person, sent to announce the year of the Lord’s favor. Through Jesus we have inherited from the Jews the practice of reading the Bible as part of the liturgy. The risen Jesus opened the minds of his disciples to understand all that referred to him in the law, the prophets and the psalms (Lk 24:44). In the homily, the priest explains the readings so that we all may know Jesus, his teachings, and instructed by his words and saved by his works we may come to salvation.
Undoubtedly the most important reading at Mass is the gospel. An ordained minister is in charge of reading it; we hear the reading standing; on more important days it is the only reading honored with incense; sometimes it is even read from a more ornate book called the gospel book. These signs underline its importance. In it Jesus himself speaks to us or episodes related to the life of Jesus are narrated. In that reading, the risen Jesus Christ becomes present in the minister who reads and in the words that are spoken. In fact, before the reading we acclaim the presence of Jesus made Word with the alleluia and, at the conclusion of the reading, the minister who read it proclaims: Word of the Lord and we all respond: Glory to you, Lord Jesus. But at the beginning of the reading we mention a human author: it is the Gospel according to St. Matthew, or St. Mark, or St. Luke or St. John.
The other two readings are also the Word of God. At the beginning of the proclamation the reader indicates the origin of the passage to be read; usually he indicates the name of the book and its author: reading from the first letter to the Corinthians by St. Paul the Apostle or reading from the book of Nehemiah. St. Paul and Nehemiah were both men. But at the end of the reading it is proclaimed: Word of God; and we all respond: We praise you, Lord.
Two questions arise. What is so special about these readings and the books from which they come? What is the origin of this practice that an important part of the rites with which we worship God consists of reading these readings taken from these books?
These readings are very special. They come from the books that constitute the holy book: the Holy Scriptures, the Holy Bible, the written Word of God. The Bible is a collection of books. Those that were written by Jews before the coming of Christ constitute the books of the Old Testament, that is, the books of the old covenant. Those other books that were written by Christians after the resurrection of the Lord constitute the books of the New Testament, that is, the books of the new covenant. The word “testament” in these names means “covenant”. There is no time to explain it, so believe me that Old and New Testament mean Old and New Covenant.