The International Sunday School Lessons (ISSL)/Uniform Series is a 6-year plan for reading and studying the entire Bible, designed to take students into every part of Scripture. The series pulls at least one lesson from nearly every book of the Bible over the 6-year cycle, following 8 specific themes[1]. The ISSL/Uniform Series has been guiding Christian education for nearly 150 years and is used by a wide spectrum of publishers and churches[2].
The ISSL/Uniform Series is created by the Committee on the Uniform Series (CUS), which includes members from a variety of denominations[2]. The CUS is a committee of the National Council of Churches, led by Dr. Tammy Wiens[3]. The series is used by churches around the world to study scripture together[2].
Various publishers produce curriculum and resources based on the ISSL/Uniform Series. One of the well-known publishers is Standard Publishing, which has been trusted by church leaders for over 100 years. They provide quality, biblically sound lessons based on the ISSL/Uniform Series through their Standard® Lesson Quarterly[4]. Another publisher is David C. Cook Publishing Co., which offers the Standard Lesson Quarterly Bible Curriculum[1][5]. The Sunday School Publishing Board also offers the Faith Series Sunday school curriculum based on the ISSL/Uniform Series for all age groups[6][7].
In summary, the International Sunday School Lessons (ISSL)/Uniform Series is a 6-year plan for studying the Bible, created by the Committee on the Uniform Series, and used by various publishers to produce curriculum and resources for churches worldwide.
Citations:
[1] https://shop.davidccook.org/collections/standard-lesson
[2] https://nationalcouncilofchurches.us/cus/
[3] https://ministry-to-children.com/international-sunday-school-lessons/
[4] https://sundayschooldirect.com/standard_adult_KJV.php
[5] https://www.cokesbury.com/standard-lesson-quarterly-niv
[6] https://www.sspbnbc.com/sunday-school-series/
[7] https://www.sspbnbc.com/sspb-digital-downloads/