The kingdom of heaven is like to a grain of mustard seed, ... which indeed is the least of all seeds: but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof. Matthew 13:31, 32. AG 17.1
The germ in the seed grows by the unfolding of the life-principle which God has implanted. Its development depends upon no human power. So it is with the kingdom of Christ. It is a new creation. Its principles of development are the opposite to those that rule the kingdoms of this world. Earthly governments prevail by physical force; they maintain their dominion by war; but the founder of the new kingdom is the Prince of Peace.... Christ implants a principle. By implanting truth and righteousness, He counterworks error and sin.... AG 17.2
The kingdom of Christ in its beginning seemed humble and insignificant. Compared with earthly kingdoms it appeared to be the least of all. By the rulers of this world Christ's claim to be a king was ridiculed. Yet in the mighty truths committed to His followers the kingdom of the gospel possessed a divine life. And how rapid was its growth, how widespread its influence! When Christ spoke this parable, there were only a few Galilean peasants to represent the new kingdom.... But the mustard seed was to grow and spread forth its branches throughout the world. When the earthly kingdoms whose glory then filled the hearts of men should perish, the kingdom of Christ would remain, a mighty and far-reaching power. AG 17.3
So the work of grace in the heart is small in its beginning. A word is spoken, a ray of light is shed into the soul, an influence is exerted that is the beginning of the new life; and who can measure its results? ... AG 17.4
In this last generation the parable of the mustard seed is to reach a signal and triumphant fulfillment. The little seed will become a tree. The last message of warning and mercy is to go to “every nation and kindred and tongue” (Revelation 14:6-14), “to take out of them a people for his name” (Acts 15:14; Revelation 18:1). And the earth shall be lightened with His glory.14Christ's Object Lessons, 77-79. AG 17.5