I'm not aware of any of them that claim to "authoritatively" interpret Scripture. Scripture itself is the sole authority, and there is only one truth. That truth is not based in Rome.
Since adding a religion doctorate from Columbia University to his technical background, he has spent 40 years systematizing information on world religions, a calling he discovered while assigned as an Anglican missionary in Africa.
Now 73, Barrett recently culminated his oddly remarkable career with publication of the second edition of his global accounting of faiths and the faithful — trends, details and his best estimated count of believers of all religions in each of 238 nations and territories.
Never has there been such a thorough reference as the two large volumes, running 1,699 pages, of the World Christian Encyclopedia, published by Oxford University Press. Barrett has doggedly visited most of the lands in person, collecting raw material, including national census figures and United Nations data, and recruiting the 444 specialists who feed him material. Among them: Vatican missions librarian Willi Henkel and editor J. Gordon Melton of the Encyclopedia of American Religions. Barrett’s encyclopedia sought to count each human being in each religion and religious subcategory in each country as of 1900, 1970, 1990, 1995 and 2000, with projections to 2025.
The 2001 edition, successor to his 1982 first edition, which took a decade to compile, identifies 10,000 distinct religions, of which 150 have 1 million or more followers.
Within Christianity, he counts 33,820 denominations.
Barrett also calculates religious populations for the Encyclopedia Britannica Book of the Year, standard estimates that are used in turn by the World Almanac and innumerable journalists. Such numbers are always debatable, but they’re the best available. “We don’t really have any rivals,” Barrett says. “That’s the problem.”
Title: World Christian Encyclopedia : a comparative survey of churches and religions in the modern world
Authors: David B. Barrett, George T. Kurian, Todd M. Johnson.
Edition: 2nd ed.
Published: Oxford ; New York : Oxford University Press, 2001.
Description: 2 v. : ill., col. maps ; 32 cm.
Notes: Includes bibliographical references and indexes.
Contents:
v. 1. The world by countries : religionists, churches, ministries
v. 2. The world by segments : religions, peoples, languages, cities, topics.