A.B. Bruce was a Scottish pastor and professor in the 19th Century. He wrote a classic about how Jesus trained his disciples, called, appropriately enough, The Training of the Twelve. In this book Bruce takes a chronological/ episodic approach, rather than a systematic or topical one, which may help to explain why the book is 550 pages long.
Bruce treats the disciples as real people, not as caricatures or buffoons. Throughout this work, he shows himself as one who clearly has soaked himself in the Word and meditated on it deeply.
In the following passage, he talks about the difference between apparent church growth and lasting Church growth. "Rousing the masses" can never replace training the few:
Where there is no obvious excitement, the church in [the view of some] is dead, and her ministry inefficient. Such [people] need to be reminded that there were two religious movements going on in the days of the Lord Jesus. One consisted in rousing the mass out of the stupor of indifference; the other consisted in the careful, exact training of men already in earnest, in the principles and truths of the divine kingdom. Of the one movement the disciples, that is, both the twelve and the seventy, were the agents; of the other movement they were the subjects. And the latter movement, though less noticeable, and much more limited in extent, was by far more important than the former; for it was destined to bring forth fruit that should remain—to tell not merely on the present time, but on the whole history of the world. The deep truths which the great Teacher was now quietly and unobservedly, as in the dark, instilling into the minds of a select band, the recipients of His confidential teaching were to speak in the broad daylight ere long ; and the sound of their voice would not stop till it had gone through all the earth. There would have been a poor outlook for the kingdom of heaven if Christ had neglected this work, and given Himself up entirely to vague evangelism among the masses.
- A.B. Bruce (1831-1899), The Training of the Twelve, p. 107
The entire book can be read or even downloaded at Google books.