This verse, when you look at the previous passage that leads up to it, has an immediate negative application: The blind students who follow after the likewise blind teachers will both fall into the ditch. And the reason is that the students have “learned” their blindness from their masters.
Further in this chapter in Luke the image changes from vision (or lack of it) to fruitfulness. A tree is known by its fruits, vs. 43-45. After this we have the straightforward teaching that those who follow Christ should obey Christ, vs. 46-49. They will be the firm house that withstand the storm.
When we are trained by Christ, by the Spirit of Christ, we will be like Him. How will we be like Him? He has communicable and non-communicable attributes. There are divine characteristics of His that we will never have: omniscience, omnipotence, and so on. But the other ones, the communicable ones, we should have (though in lesser degree). This is having Christ formed in us.
Getting back to Christ as Prophet, Priest, and King. We are also to be like Him in these ways.
Moses,when told that there were Eldad and Medads were prophesying in the camp responded,
“Oh, that all the LORD’s people were prophets and that the LORD would put His Spirit upon them!”
These words were not just a vain or off-the-cuff words of exasperation from Moses, but evidently a prophetical glimpse into the future, looking far into that dispensation that would supplant the Covenant of Moses’ time. Paul repeats this very sentiment in 1 Cor. 14:1-5:
1 Pursue love, and desire spiritual gifts, but especially that you may prophesy.
2 For he who speaks in a tongue does not speak to men but to God, for no one understands him; however, in the spirit he speaks mysteries.
3 But he who prophesies speaks edification and exhortation and comfort to men.
4 He who speaks in a tongue edifies himself, but he who prophesies edifies the church.
5 I wish you all spoke with tongues, but even more that you prophesied; for he who prophesies is greater than he who speaks with tongues, unless indeed he interprets, that the church may receive edification.
But now we have a problem. According to this same letter of Paul, in the previous chapter, prophesying (along with tongues and knowledge) will be done away with. When? “When that which is perfect is come.” To the Preterist this is already a past event with an everlasting present reality. The Perfect has come.
Fore-telling and Forth-telling
So what about prophesying? There are two types of prophesying. The first is fore-telling. This is the forecasting of events by divine inspiration. The writers of the Bible had this. But when the prophesying ceased the canon of Scripture was finalized (although not recognized as such by Christians until much later). The perfect had come and did away with that type of prophesying.
But the other type of prophesying is still around and very much needed. And that is forth-telling. This is the bringing forth to the world what is in the Word of God, telling others what we have been taught.
Christ asked His disciples, Matt. 13:50-52:
“Have you understood all these things?”
They said to Him, “Yes, Lord.”
Then He said to them, “Therefore every scribe instructed concerning the kingdom of heaven is like a householder who brings out of his treasure things new and old.”
As we are trained – and to the extent that we have been trained – we too are bringing out of the treasury of the Bible things new and old, Old Testament promise matched to New Testament clarification. The Prophets of the Bible prophesied this way, along with their inspired predictive discourses.
It is in this first sense that all Christians are to be prophets.