It is used throughout Paul's letter to the Romans. It refers to God's extending of unmerited favor toward mankind so they might come to enjoy a sanctified peaceful relationship with him. A prayer said before a meal. The literature often speaks of Jehovah's grand purposes. In these contexts it is appropriate.
Some people say they are of the great crowd when they really mean they are of the other sheep.
Parts of this are reiterated from a different viewpoint in other Gospels. The series of events that culminates in God's war of Armageddon and the abyssing of Satan. This package has been out of print for many years, but one occasionally sees one floating around. More important than the cover is the text, which has been updated several times since the green cover was last used. Because Witnesses tend to wear Bibles out at the rate of one a year or so, anyone who still uses a green Bible regularly probably does not read it, and is seriously out of pace with the organization.