Key Greek words used in biblical texts that decide the meaning of the text.

The generation

THE CONTEXT OF JESUS' CURSING OF THE FIG TREE 

THE MOSAIC PRIESTHOOD AND MOSAIC LEADERSHIP OF ISRAEL 

Matthew 21:45
And when the chief priests and Pharisees heard His parables, they knew that He spoke of them.

THEY WERE ANGRY

MATTHEW 21:
15 And when the chief priests and scribes saw the wonderful things which He did, and the children crying in the temple, and saying, Hosanna to the Son of David, they were angry.

19 And seeing a fig tree in the way, He came to it and found nothing on it except leaves only. And He said to it, let no fruit grow on you forever. And immediately the fig tree withered away.

The above fig tree will never again produce any leaves or fruit, as Jesus said when He cursed it - because in its context it was a reference to the Sadducees, priests, scribes and Pharisees, "who knew that He spoke of them":

23 And when He had come into the temple, the chief priests and the elders of the people came to Him as He was teaching, and said, By what authority do you do these things? And who gave you this authority?

During His reply, Jesus told them a parable which ended with the question, 

31 "Which of the two did the will of his father?" To which they replied, "The first". Jesus said to them, "Truly I say to you that the tax-collectors and the harlots go into the kingdom of God before you.​" 

(Jesus based the above statement on their reply, implying that they were not doing the will of God).

Then Jesus told them another parable, which ended with the words,

39-41: "And taking him, they threw him out of the vineyard and killed him. Therefore when the lord of the vineyard comes, what will he do to those vinedressers? They said to Him, Bad men! He will miserably destroy them and will rent out his vineyard to other vinedressers who will give him the fruits in their seasons."

To which Jesus replied,

  43 "Therefore I say to you, The kingdom of God shall be taken from you and given to a nation bringing out its fruits.

  45 And when the chief priests and Pharisees heard His parables, they knew that He spoke of them.

1 Peter 2:
   9 But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:
   10 Which in time past were not a people, but are now the people of God: which had not obtained mercy, but now have obtained mercy.

Hebrews 7
  12 For the priesthood being changed, there is of necessity a change made in the law also.
 13 For He of whom these things are spoken belongs to another tribe, from which no man gave attendance at the altar.
  14 For it is evident that our Lord sprang out of Judah, of which tribe Moses spoke nothing concerning priesthood.
  15 And it is still far more evident, since there arises a different priest after the likeness of Melchizedek,
  16 who is made, not according to the law of a fleshly commandment, but according to the power of an endless life.
  17 For He testifies, "You are a priest forever after the order of Melchizedek."

Jesus is a priest forever. The old priesthood has gone forever. The fig tree that was cursed by Jesus will never again bear fruit. The cursing of the fig tree was to do with who has the authority in the Kingdom of God: Jesus? or the priests, the Pharisees, and the scribes?
We should not misapply the PARABLE of the cursed fig tree, ignoring the context, and then misconstrue Christ's analogy of A fig tree showing leaves to mean something that begins with the words "When Israel begins to.. "

THIS GENERATION

Jesus was often talking about the 1st century generation when He said "this generation", but it's a logical fallacy to assume that every time Jesus said "this generation", He was talking about the 1st century generation, because there is no difference in meaning between the English words "this generation", "that generation", "the generation/s", "ancient generations" etc, and the Greek words that they are translated from:

Talking about the generation in the wilderness during the days of Moses:

Hebrews 3:10: "Therefore I was grieved with that generation [o genea] and said, They always err in their heart, and they have not known My ways."

Many generations:

Colossians 1:26: 
".. the mystery which has been hidden from ages and from generations [o genea], but now has been revealed to His saints."

All generations:

Ephesians 3:21 "To him be the glory in the church and in Christ Jesus to all generations [o genea], to the ages of the ages. Amen."

Many generations:

Acts 15:21: 
"For Moses from ancient generations [genea] has those in every city proclaiming him, being read in the synagogues every sabbath day."

Acts 14:16 
"who in past generations [genea] allowed all nations to walk in their own ways."

One generation:

Acts 13:36: 

"For after he had served his own generation [genea] by the will of God, David fell asleep and was added to his fathers and saw corruption."

The above verses are all talking about the generation that is, or the generations that are being referred to in whichever verses the words appear.

Jesus' own generation:

Luke 17:25: 
"But first He must suffer many things and be rejected of this [houtos] the generation [o genea].

Luke 11:31: 
"The queen of the south shall rise up in the Judgment with the men of this [houtos] the generation [o genea] and condemn them. For she came from the ends of the earth to hear the wisdom of Solomon. And behold, One greater than Solomon is here."

The generation that will see the end of the age:

Luke 21:31-32: 
"So also, when you see these things happening, know that the kingdom of God is near. Truly I say to you, The same [houtos] the generation [o genea] shall not pass away until all these things are fulfilled."

The context of the surrounding passage decides what time or period in history it's referring to, and which generation is being spoken about. In the case of Luke 21:31-32, it's referring to the generation that will see the signs of the end of the Age that Jesus gave in the Olivet Discourse.

CHECKING THE CONTEXT

Jesus is referring to the signs that He had just given regarding the end of the age and time of His return when He says,

"Behold the fig-tree and all the trees. Now when they sprout leaves, seeing it you will know that summer is now near. So also, when you see these things happening, know that the kingdom of God is near". Luke 21:29-31.
We can't just go adding a veiled reference to something other than what Jesus was talking about in the above verses - and He was talking about the signs of the end of the age, and His return, nothing else. 

It has nothing to do with the fig tree that Jesus had earlier cursed: That fig tree will never again produce any leaves or fruit, as Jesus said when He cursed it - because it was a reference to the Sadducees, priests, scribes and Pharisees, "who knew that He spoke of them".

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