Tenrikyo uses the metaphor of construction to describe God's work of world salvation―that is, the work of building the world of the Joyous Life, which refers to God's ideal world―and the term "Yoboku" means "timber," or building material for the construction of the Joyous Life World. In effect, Yoboku are those who endeavor to spread the Tenrikyo teachings that will enable humankind to realize the Joyous Life.

The use of this term is based on the Ofudesaki, which says, for instance:

Just a word: the hastening in the mind of God is solely to prepare to assemble useful timber.

Of these timbers, it is not to be just a few. I desire a great number of timbers.

III:128, 130

These verses indicate that God desires a great many Yoboku, who are to serve as "timber" for building the Joyous Life World. Yet the quantity of Yoboku is not the only thing that matters; their quality is also important. Says the Ofudesaki:

Day by day, I shall tend those trees which are to become My useful timber. Never take it to be illness.

Among the trees, there will be some that I shall tend step by step and others that I shall let fall as they are.

III:131-132

Though I have gathered many and varied trees, those bent or crooked are of no use.

III:50

The Scripture thus indicates that God's construction requires a large number of Yoboku who are of good quality. Because God is working on a huge undertaking, which is to save the entire world, God seeks a great many Yoboku to help reach out to people throughout the world. In addition, their quality needs to be appropriate, just as the shape and characteristics of building materials need to be appropriate.

When Yoboku, grounded in their sense of mission, strive to achieve single-hearted salvation in order to bring about the Joyous Life World, wondrous salvation can come about, whereby people can overcome suffering and anxiety.

Step by step, the Parent, who began this world, will enter all of these useful timbers.

When the Parent, who began this world, enters them, there is no knowing what I shall do.

XV:60-61

The aforementioned wondrous salvation is God's response to the sincerity of Yoboku who are engaged in single-hearted salvation―their true sincerity in wanting to do whatever it takes to have someone saved―and comprises the unimaginable workings and marvelous blessings that God provides by entering the Yoboku. It is through such workings and blessings of God that Tenrikyo's mission can make progress.

Thus, Yoboku play an intermediary role in allowing God's wondrous salvation to flow forth so as to help people overcome suffering and anxiety. In the process, they also contribute to conveying the teachings that embody God's intention to bring about the Joyous Life.

The term "Yoboku" came into general use in Tenrikyo after its post-war effort to restore the teachings made the Scriptures more widely available and led to the publication in 1949 of Tenrikyo Kyoten (the Japanese original of The Doctrine of Tenrikyo). One of the ten chapters of this book, chapter nine, is entitled "Yoboku."

In 1959, when the Constitution of Tenrikyo was revised, the terms "followers," "Yoboku," and "kyoto" (minister) were adopted to describe three classifications of members of the Tenrikyo community. Thus, "Yoboku" became a term that reflects where one stands in terms of degrees of commitment to Tenrikyo. According to this usage, a Yoboku is a person who has received the truth of the Sazuke, which can be bestowed on a follower who is seventeen years of age or older and has attended a series of nine Besseki lectures at Tenrikyo's headquarters.

It may be noted that this definition of the term "Yoboku" was introduced purely for the sake of convenience. As far as the Ofudesaki is concerned, the significance of being Yoboku is to serve in God's work of salvation as the instruments of Oyasama.

Oyasama's purpose in using Yoboku as Her instruments is to realize the Joyous Life, God's ideal world. It is for this purpose that She taught the path of single-hearted salvation. This path comprises the performance of the Salvation Service and the administration of the Sazuke. Another aspect of the path is to bring the teachings to greater numbers of people.

(This article was first published in the July 2009 issue of TENRIKYO.)