John Bunyan was a great writer in metaphors/parables and he explains the use of them in his "The Barren Fig Tree" work (http://www.chapellib.../bun-barren.pdf):
6 He spake also this parable; A certain man had a fig tree planted in his vineyard; and he came and sought fruit thereon, and found none.
7 Then said he unto the dresser of his vineyard, Behold, these three years I come seeking fruit on this fig tree, and find none: cut it down; why cumbereth it the ground?
8 And he answering said unto him, Lord, let it alone this year also, till I shall dig about it, and dung it:
9 And if it bear fruit, well: and if not, then after that thou shalt cut it down. - Luke 13:6-9
In parables there are two things to be taken notice of, and to be inquired into of them that read.
First, The metaphors made use of.
Second, The doctrine or mysteries couched under such metaphors.
The metaphors in this parable are,
1. A certain man;
2. A vineyard;
3. A fig-tree, barren or fruitless;
4. A dresser;
5. Three years;
6. Digging and dunging, &c.
The doctrine, or mystery, couched under these words is to show us what is like to become of a fruitless or formal professor. For,
1. By the man in the parable is meant God the Father (Luke 15:11).
2. By the vineyard, his church (Isa 5:7).
3. By the fig-tree, a professor.
4. By the dresser, the Lord Jesus.
5. By the fig-trees barrenness, the professors fruitlessness.
6. By the three years, the patience of God that for a time he extendeth to barren professors.
7. This calling to the dresser of the vineyard to cut it down, is to show the outcries of justice against fruitless professors.
8. The dresser's interceding is to show how the Lord Jesus steps in, and takes hold of the head of his Father's axe, to stop, or at least to defer, the present execution of a barren fig-tree.
9. The dresser's desire to try to make the fig-tree fruitful, is to show you how unwilling he is that even a barren fig-tree should yet be barren, and perish.
10. His digging about it, and dunging of it, is to show his willingness to apply gospel helps to this barren professor, if haply he may be fruitful.
11. The supposition that the fig-tree may yet continue fruitless, is to show, that when Christ Jesus hath done all, there are some professors will abide barren and fruitless.
12. The determination upon this supposition, at last to cut it down, is a certain prediction of such professors unavoidable and eternal damnation.
But to take this parable into pieces, and to discourse more particularly, though with all brevity, upon all the parts thereof. 'A certain MAN had a fig-tree planted in his vineyard.' The MAN, I told you, is to present us with God the Father; by which similitude he is often set out in the New Testament. Observe then, that it is no new thing, if you find in Gods church barren fig-trees, fruitless professors; even as here you see is a tree, a fruitless tree, a fruitless fig-tree in the vineyard.
Fruit is not so easily brought forth as a profession is got into; it is easy for a man to clothe himself with a fair show in the flesh, to word it, and say, Be thou warmed and filled with the best. It is no hard thing to do these with other things; but to be fruitful, to bring forth fruit to God, this doth not every tree, no not every fig-tree that stands in the vineyard of God. Those words also, 'Every branch in me that beareth not fruit, he taketh away,' assert the same thing (John 15:2). There are branches in Christ, in Christs body mystical, which is his church, his vineyard, that bear not fruit, wherefore the hand of God is to take them away: I looked for grapes, and it brought forth wild grapes, that is, no fruit at all that was acceptable with God (Isa 5:4). Again, 'Israel is an empty vine, he bringeth forth fruit unto himself,' none to God; he is without fruit to God (Hosea 10:1). All these, with many more, show us the truth of the observation, and that God's church may be cumbered with fruitless fig-trees, with barren professors.
Your post is giving me a Déjà vu moment as poor old John Bunyan and many others have got the parable so wrong.
I have previously posted on this parable and I will do so again.
This parable was told to a Jewish audience and the brief outline of this parable is that if Israel does not repent of their evil deeds by the end of the fourth age when it is inspected for good fruit produced by or at the end of the fourth age, then the fig tree at the very start of the fifth age of its existence will be cut down and destroyed by being thrown in the fire.
Jesus also said this in the following verses: -
Matthew 7:15-20 You Will Know Them by Their Fruits
(Matt 12:33; Luke 6:43-45)
15 "Beware of false prophets, who come to you in sheep's clothing, but inwardly they are ravenous wolves.
16 You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles?
17 Even so, every good tree bears good fruit, but a bad tree bears bad fruit.
18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit.
19 Every tree that does not bear good fruit is cut down and thrown into the fire. 20 Therefore by their fruits you will know them.
Let me unpack this parable a little for you: -
The Fig Tree God planted began with the birth of Isaac. (Isaac's birth was the confirmation of God's covenant undertakings made with Abraham, and whose descendants were to become know as Israel.) Around 1,000 plus years later, God inspects the fig tree and finds no good fruit. Likewise after another 1,000 plus years had passed, God inspected the fig tree and found no good fruit, and then after the third season of 1,000 plus years, when He had inspected the Fig Tree and found no good fruit, he said to the dresser of the vineyard, to cut down the fig tree and asked the Dresser why should the fig tree draw nourishment from the soil also if it will not produce good fruit.
However, the Dresser responded and requested that another season, about 1,000 plus years of grace be given to the fig tree and if no good fruit is to be found then, the Dresser conceited that God could cut down the Fig tree at that time.
This parable was a warning to All of Israel, that if they did not repent of their continuous idolatrous practices that by the end of the fourth age, and turn once more into a covenant relationship with God that He, God, would destroy them from the face of the earth.
There are many prophetic verse in the Old Testament that tells us that after the passing of four ages/days of the Lord, that Israel will turn again back to God and that God will make like new again the Kingdom of Priests, a Holy Nation and God's possession among the Nations Covenant so that the covenant is fresh and meaningful once more for the remnant of Israel.
Sadly, this parable, like the Parable of the Talents has been used by zealous preachers to "wrongly encourage" their congregation to work hard to bring in the Kingdom of God so that the End Times will become imminent. God has a plan for the church, but that Plan as Paul tells us is to make Israel Jealous of the Gentile Church such that they too renew their relationship with God.
In this Parable, Jesus hints at when the visitation of the iniquities during the third and the fourth
{age} of the fathers on their Children and their Children's children, will be finished. We also know from OT prophecies that after the the two ages of the visitation of the iniquities for two ages, that God will hear their cries once more and will begin to gather the remnant of Israel to Himself for His purposes.
Although John Bunyan was well intended, I would question his motive as to why he has interpreted this parable in this manner.
Not every past commentator should be easily accepted as presenting the truth.
The above application of this parable by John Bunyan to the church is not applicable with respect to this parable as recorded in Luke 13:6-9 whoever the above Matthew 7:15-20 passage was applicable to the message John Bunyan was attempting to present and he did make a passing reference to it in the above passage.
Shalom