ROOTS is part of the Growth Model manual series books. ROOTS ground-works is a workbook that is a 6 Weeks Challenge to grow spiritually focusing on the Disciplines of Christian life. Although the Focus is on these disciplines it is designed to allow growth in all the areas of growth including Critical Truths.
The best practice is to allow a disciple to work this through with a Christian that has already completed this challenge. Spiritual growth is caused by answering critical questions is this is most effectively done in the biblical manner of discipleship.
This is a free resource. Download and enjoy.