Four stories about Jesus seeking fruit on a Fig Tree
Mark 11:12 And on the morrow, when they were come out from Bethany, he hungered. 13 And seeing a fig tree afar off having leaves, he came, if haply he might find anything thereon: and when he came to it, he found nothing but leaves; for it was not the season of figs. 14 And he answered and said unto it, No man eat fruit from thee henceforward for ever. And his disciples heard it...
19 And every evening he went forth out of the city. 20 And as they passed by in the morning, they saw the fig tree withered away from the roots. 21 And Peter calling to remembrance saith unto him, Rabbi, behold, the fig tree which thou cursedst is withered away. 22 And Jesus answering saith unto them, Have faith in God. 23 Verily I say unto you, Whosoever shall say unto this mountain, Be thou taken up and cast into the sea; and shall not doubt in his heart, but shall believe that what he saith cometh to pass; he shall have it. 24 Therefore I say unto you, All things whatsoever ye pray and ask for, believe that ye receive them, and ye shall have them.
Matthew 21:18 Now in the morning as he returned to the city, he hungered. 19 And seeing a fig tree by the way side, he came to it, and found nothing thereon, but leaves only; and he saith unto it, Let there be no fruit from thee henceforward for ever. And immediately the fig tree withered away. 20 And when the disciples saw it, they marvelled, saying, How did the fig tree immediately wither away? 21 And Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do what is done to the fig tree, but even if ye shall say unto this mountain, Be thou taken up and cast into the sea, it shall be done. 22 And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.
This story is not in Luke. However, there is another story about fig trees in Luke that is not in Mark and Matthew. It may seem unrelated, but not really.
6 And he spake this parable; A certain man had a fig tree planted in his vineyard; and he came seeking fruit thereon, and found none. 7 And he said unto the vinedresser, Behold, these three years I come seeking fruit on this fig tree, and find none: cut it down; why doth it also cumber the ground? 8 And he answering saith unto him, Lord, let it alone this year also, till I shall dig about it, and dung it: 9 and if it bear fruit thenceforth, well; but if not, thou shalt cut it down.
So then, let's consider this from the view that Luke refers to those prior to the rapture, Mark is the tribulation saints and Matthew is Israel at the end of the age. In every case Jesus is seeking fruit. The watchmen need a little fertilizer boost to get going prior to the rapture, meanwhile for Mark the apostate church would be the Fig tree without any fruit that is cursed and withers up and for the Jews in Matthew it would be their synagogues that are fruitless and are cursed and wither up.
Now with that as a context lets consider the reference to the fig tree in the gospel of John.
John 1:48 Nathanael saith unto him, Whence knowest thou me? Jesus answered and said unto him, Before Philip called thee, when thou wast under the fig tree, I saw thee. 49 Nathanael answered him, Rabbi, thou art the Son of God; thou art King of Israel. 50 Jesus answered and said unto him, Because I said unto thee, I saw thee underneath the fig tree, believest thou? thou shalt see greater things than these. 51 And he saith unto him, Verily, verily, I say unto you, Ye shall see the heaven opened, and the angels of God ascending and descending upon the Son of man.
You will see heaven opened and the angels of God ascending and descending on the Son of Man. This could certainly be seen as a reference to prayer which we see in both Mark and Matthew, and it could also be seen as a reference to the rapture.
Obviously what makes the fig tree special is the reference in Genesis to Adam and Eve using the fig leaves to cover their nakedness. Yes, the fig tree is a national symbol of Israel. But Adam and Eve predate Israel so the significance for all of us is that we use these leaves (the good works) to cover up our nakedness due to sin. This doesn't mean that the fig tree is bad, only that Jesus redemptive sacrifice on the cross is far superior (I'd rather be covered with skins than fig leaves). Jesus saw Nathaniel "under the fig tree" reminds us of Adam and Eve covering themselves with fig leaves. Jesus sees our heart, He sees our good works, but the greater thing is answered prayer. The greater thing that the whole world will see is the rapture.