The Catholic Lectionary web site has some detailed statistics on books and verses from the bible used in Sunday and Weekday masses – pre Vatican II and after. The statistics take into account the full lectionary (except Psalms) which does change according to the established yearly cycles – see more information on the lectionary at the bottom of this post.
Here is a summary of Old and New Testament readings
Check the Catholic Lectionary site for details by book and other commentary. Note Psalm usage is not included since since they are used so often in various ways during the Mass
43 of the 46 books of the Old Testament are used (1 Chronicles, Judith and Obadiah are not used)
Some tables I created from the site’s data:
Old Testament books with highest % of use
Old Testament book with highest number of verses used
27 of the 27 books of the New Testament are used
Some tables I created from the site’s data:
NewTestament books with highest % of use
New Testament book with highest number of verses used
The bishops assembled at Vatican II declared, “The treasures of the Bible are to be opened up more lavishly so that a richer fare may be provided for the faithful at the table of God’s word. In this way the more significant part of the Sacred Scriptures will be read to the people over a fixed number of years” (Sacrosanctum Concilium, #51).
How are Sunday Readings Chosen?
See this article in US Catholic
Excerpt: “The earliest Christians simply read whatever scriptures were available in their community. The first “lectionaries,” appearing by the fifth or sixth century, were actually just Bibles with notes in the margins telling the reader which passage to read on a particular Sunday.”
What is the Lectionary?
See USCCB site for the following text and other details.
Do we read from the Bible at Mass?
“Readings from Scripture are part of every Mass. At least two readings, one always from the Gospels, (3 on Sundays and solemnities) make up the Liturgy of the Word. In addition, a psalm or canticle is sung.
These readings are typically read from a Lectionary, not a Bible, though the Lectionary is taken from the Bible.”
What’s the difference between a Bible and a Lectionary?
“A Lectionary is composed of the readings and the responsorial psalm assigned for each Mass of the year (Sundays, weekdays, and special occasions). The readings are divided by the day or the theme (baptism, marriage, vocations, etc.) rather than according to the books of the Bible. Introductions and conclusions have been added to each reading. Not all of the Bible is included in the Lectionary.
Individual readings in the Lectionary are called pericopes, from a Greek word meaning a “section” or “cutting.” Because the Mass readings are only portions of a book or chapter, introductory phrases, called incipits, are often added to begin the Lectionary reading, for example, “In those days,” “Jesus said to his disciples,” etc.”
How is the Lectionary arranged?
The Lectionary is arranged in two cycles, one for Sundays and one for weekdays.
“The Sunday cycle is divided into three years, labeled A, B, and C. 2008 was Year A. 2009 was Year B, 2010 is Year C, etc. In Year A, we read mostly from the Gospel of Matthew. In Year B, we read the Gospel of Mark and chapter 6 of the Gospel of John. In Year C, we read the Gospel of Luke. The Gospel of John is read during the Easter season in all three years. The first reading, usually from the Old Testament, reflects important themes from the Gospel reading. The second reading is usually from one of the epistles, a letter written to an early church community. These letters are read semi-continuously. Each Sunday, we pick up close to where we left off the Sunday before, though some passages are never read.”
The weekday cycle is divided into two years, Year I and Year II. Year I is read in odd-numbered years (2009, 2011, etc.) and Year II is used in even-numbered years (2010, 2012, etc.) The Gospels for both years are the same. During the year, the Gospels are read semi-continuously, beginning with Mark, then moving on to Matthew and Luke. The Gospel of John is read during the Easter season. For Advent, Christmas, and Lent, readings are chosen that are appropriate to the season. The first reading on weekdays may be taken from the Old or the New Testament. Typically, a single book is read semi-continuously (i.e., some passages are not read) until it is finished and then a new book is started.
The year of the cycle does not change on January 1, but on the First Sunday of Advent (usually late November) which is the beginning of the liturgical year.
In addition to the Sunday and weekday cycles, the Lectionary provides readings for feasts of the saints, for common celebrations such as Marian feasts, for ritual Masses (weddings, funerals, etc.), for votive Masses, and for various needs. These readings have been selected to reflect the themes of these celebrations.