Lu 13:18  Then said he, Unto what is the kingdom of God like? and whereunto shall I resemble it?
 19 It is like a grain of mustard seed, which a man took, and cast into his garden; and it grew, and waxed a great tree; and the fowls of the air lodged in the branches of it.

The mustard seed refers to the Lord Jesus Christ. He is the living seed. He was despised, rejected and crucifed and buried and rose on the third day. He is the seed of David, the Messiah, where the Old Testament prophets were looking forward and the Old Testament saints were saved by faith looking forward to the cross. Jesus said,  "Verily, verily, I say unto you, Except a corn of wheat fall into the ground and die, it abideth alone: but if it die, it bringeth forth much fruit." (Joh 12:24 ) The seed is the word of God. This word of God bears the gospel. During the time of Noah's days, the coming judgement was preached, and there was the good news where one can escape the judgement as Noah built an Ark. Everyone mocked at Noah as he was building a boat. The judgement came and only Noah and his family was saved. The good news is they were saved from the wrath of God. It is the same with Sodom and Gomorrah. There was the good news for Lot and his family as they were saved from the wrath of God. Except for Lot's wife who was disobedient. We see here only a remnant is saved.

When we go to the Old Testament we see after the death of Soloman the united kingdom was divided in to two.  The northern kingdom, which was called Isarael and the southern kingdom which was called Judah. The tribe of Benjamin and the Judah was in the southern kingdom and the balance ten tribes were in the nothern kingdom.  For the first sixty years the kings of Judah aimed at re-establishing their authority over the kingdom of the other ten tribes, so that there was a state of perpetual war between them. For the next eighty years there was no open war between them. For the most part they were in friendly alliance, co-operating against their common enemies. God sent prophets to Israel and to Judah warning them against false prophets who were preaching peace and prosperity and not exposing the sins of the people. Outwardly, the nation was enjoying a time of prosperity and growth; but inwardly, moral corruption and spiritual adultery permeated the lives of the people.They persecuted the true prophets of God and killed them.

The nothern kingdom was called Israel. The capital city was Samaria. Amos, Hosea and Jonah were the prophets in Israel. Isaiah, Jeremiah, Habakkuk,Joel, Micach, Nahum and Zephaniah served as prophtes in Judah. The Old Testament of our Bible is arranged according to topical order but the Jewish Old Testamen is arranged according to chronological order. Obadiah was written durinng the destruction of Jerusalem,  Daniel and Ezkiel  were written during the time of exile. Then Ezra, Nehemiah, Haggai and Malachi was wrtten after the exile in returning back to Jerusalem.

Ezekiel was conemporary to Daniel. Hosea was contemparay to Isaiah, Amos, Jonah.  Jeremiah was contemporary to Obadiah,  and Zephaniah.

 Jer 14:14 Then the LORD said unto me, The prophets prophesy lies in my name: I sent them not, neither have I commanded them, neither spake unto them: they prophesy unto you a false vision and divination, and a thing of nought, and the deceit of their heart.
 La 2:14 Thy prophets have seen vain and foolish things for thee: and they have not discovered thine iniquity, to turn away thy captivity; but have seen for thee false burdens and causes of banishment.

The people of Judah and Israel beleived the false prophets as their message pleased the flesh. They too used the word of God, as we know Satan quoted scripture to the Lord Jesus, and Satan can transform like an angel of light. These false prophets were from the devil and when the true prophets of God were preaching of repentance and the judgment of God, people never believed them. The reason is that they were living in peace and comfort with much security.  How can an enemy destroy Jerusalem when there was a thick wall of stones build around the city. The people were comfortable in the temple of the Lord but they were worldly and comfortable Christians at that time.

Fall of Israel
The Assyrian empire (650 BC) extended from Babylon to Egypt. Then suddenly God's judgment came to the northern kingdom Isarael when the Assyrians came and destroyed Israel but a remnant was scattered throughout the east as far as the Caspian Sea

 2Ki 17:13 Yet the LORD testified against Israel, and against Judah, by all the prophets, and by all the seers, saying, Turn ye from your evil ways, and keep my commandments and my statutes, according to all the law which I commanded your fathers, and which I sent to you by my servants the prophets.
 14 Notwithstanding they would not hear, but hardened their necks, like to the neck of their fathers, that did not believe in the LORD their God.
 18 Therefore the LORD was very angry with Israel, and removed them out of his sight: there was none left but the tribe of Judah only.
 2Ki 17:20 And the LORD rejected all the seed of Israel, and afflicted them, and delivered them into the hand of spoilers, until he had cast them out of his sight.
 2Ki 17:24 And the king of Assyria brought men from Babylon, and from Cuthah, and from Ava, and from Hamath, and from Sepharvaim, and placed them in the cities of Samaria instead of the children of Israel: and they possessed Samaria, and dwelt in the cities thereof.

Fall of Assyria
Pr 21:1 The king's heart is in the hand of the LORD, as the rivers of water: he turneth it whithersoever he will.
Babylon rebelled against the Assyrian Empire in 626 b.c., overthrew the Assyrian capital of Nineveh in 612 b.c., and became master of the ancient Near East when it defeated Egypt at the battle of Carchemish in 605 b.c. Assyria fell according to the prophecies of Isaiah (10:5-19), Nahum (3:19), and Zephaniah (3:13)

Fall of Judah
 Isa 14:24 The LORD of hosts hath sworn, saying, Surely as I have thought, so shall it come to pass; and as I have purposed, so shall it stand:
Then we see the fall of the southern kingdom. The fall of Jerusalem. After Jehoiakim revolted, Jerusalem fell again to Nebuchadnezzar in 597 b.c. The temple was looted and the treasures were taken back to Babylon. A third Babylonian siege of Jerusalem followed Zedekiah’s revolt (589 b.c.) and the city fell in July of 587 or 586 b.c.

The Captivity
In the third year of Jehoiachim, the eighteenth king of Judah (B.C. 605), Nebuchadnezzar having overcome the Egyptians at Carchemish, advanced to Jerusalem with a great army. After a brief siege he took that city, and carried away the vessels of the sanctuary to Babylon, and dedicated them in the Temple of Belus (2 Kings 24:1; 2 Chr. 36:6, 7; Dan. 1:1, 2). He also carried away the treasures of the king, whom he made his vassal. At this time, from which is dated the "seventy years" of captivity (Jer. 25; Dan. 9:1, 2)

Remnant
When Assyrans captured the northern kingdom Israel there was a remnant that was scattered. God also protected a remant of Judah when they were taken to Babylon. The following are some prophecies.

 2Ch 30:6 So the posts went with the letters from the king and his princes throughout all Israel and Judah, and according to the commandment of the king, saying, Ye children of Israel, turn again unto the LORD God of Abraham, Isaac, and Israel, and he will return to the remnant of you, that are escaped out of the hand of the kings of Assyria.
 2Ki 19:31 For out of Jerusalem shall go forth a remnant, and they that escape out of mount Zion: the zeal of the LORD of hosts shall do this.
 2Ki 25:11 Now the rest of the people that were left in the city, and the fugitives that fell away to the king of Babylon, with the remnant of the multitude, did Nebuzaradan the captain of the guard carry away.
 Isa 1:9 Except the LORD of hosts had left unto us a very small remnant, we should have been as Sodom, and we should have been like unto Gomorrah.

Cyrus Captures Babylon.
When Cyrus the Persian captured Babylon in 539 b.c., government controls on captive peoples were loosened and the way was opened for exiled Judah to begin the return to her homeland. The ascension and victory of Cyrus fulfilled the prophecy of Isaiah 44:28-45:4.

The Remnant Returning Back to Jerusalem.
Just as the Israelites were taken into exile in three successive stages (605, 597, 586 b.c.), they returned in three stages. The first occurred under the leadership of Zerubbabel (c. 538 b.c.). After considerable delay, this return resulted in the rebuilding of the temple (c. 520-516 b.c.), encouraged by the prophets Haggai and Zechariah. Ezra led the second return in the seventh year of Artaxerxes I (c. 458 b.c.). Nehemiah led the final return in the twentieth year of Artaxerxes I (c. 444 b.c.)

During the period covered by the book of Ezra, Gautama Buddha (c. 560-480 b.c.) was in India, Confucius (551-479 b.c.) was in China, and Socrates (470-399 b.c.) was in Greece.

2Ch 34:9 And when they came to Hilkiah the high priest, they delivered the money that was brought into the house of God, which the Levites that kept the doors had gathered of the hand of Manasseh and Ephraim, and of all the remnant of Israel, and of all Judah and Benjamin; and they returned to Jerusalem.
 Ezr 3:8 Now in the second year of their coming unto the house of God at Jerusalem, in the second month, began Zerubbabel the son of Shealtiel, and Jeshua the son of Jozadak, and the remnant of their brethren the priests and the Levites, and all they that were come out of the captivity unto Jerusalem; and appointed the Levites, from twenty years old and upward, to set forward the work of the house of the LORD.
 Ne 1:3 And they said unto me, The remnant that are left of the captivity there in the province are in great affliction and reproach: the wall of Jerusalem also is broken down, and the gates thereof are burned with fire.

Birds of the Air
In the New Testament we see the miracle of Jesus by feeding five thousand people and a great crowd followed him. But when he told the doctrine of election many left him.  "And he said, Therefore said I unto you, that no man can come unto me, except it were given unto him of my Father.  From that time many of his disciples went back, and walked no more with him." (Joh 6:65 -66) The great crowd dissapeard and only about 120 people were praying in the upper room when the just before the Holy Spirit came upon them. (Acts 1:15) Then we see 3000 people getting saved in one day after the sermon of Peter, and the church began to grow. Then we see how Nero persecuted the church, crucified the Christians and burned them alive. The Roman Emperors hunted the Christians and many were martyered for their faith in Christ. There was still a remnant scattered who did not give up their faith in spite of the persecution. Then came the Popes who took over the church after Constantine, the gospel was kept in silence and it did not grow.  These were the dark ages where the Roman Catholic Church put the gospel asleep in the libraries and in monasteries, till Luther, Calvin and the other reformers put the gospel back into the minds of men. There  was again the growth of the gospel, with the growth came the brids that nested on the branches. There is sin in the church. The Arminan gospel is flourshing it is becoming bigger and bigger. False teachings are rampant in the churches, as it is sugar coated with the true word of God and the imature Christian cannot distinguish or discern as false teachings comes from the pulpit using the Bible and it relates to their practical living, oh! it pleases the flesh.

Example of Nehemiah
Many of the  reform churches are sleeping too. They will not expose the false teachings of the church, rather they  will compromise by saying although they teach false doctrines they are Christians too. Do you see the picture my friends, we are living in the times of Isaiah and Jeremiah. There is only a remnant that is serving the Lord. We need to wake up! and realize the church is in a bad condition. Cry out like Nehemiah, with mourning, fasting and prayer. Not potluck, feasting and prayer. We need to pray like Nehemiah saying confessing the sins of the church. We need to plan like Nehemiah, as the first thing he did was to go and survey the city, build a plan. Carried out the plan with great skill and energy. The enemy came with very skillful accusations against Nehemiah and told Nehemiah to come down, Nehemiah said, "I am doing a great work and I cannot come down, why should the work cease while I leave it and go down to you?" (Neh 6:3) The enemy craftily engaged problems to arise within the church, Nehemiah prayed and dealt with the problems without stopping the work. The building of the walls were completed in 52 days!. (Neh 6:15) We should not just exist as Christians, coming to church on Sunday, listening to a sermon and go home but serving the living God.

Self Denial
In John Calvin's Christian Life he mentions the first step is to have a self denial. Obey the will of God as we are not our own, he who neglects self denial is deceived by pride and hypocrisy. We cannot serve the Lord unless we practise self denial. If we do not have self denial we will be conformed to the world. We need to serve the Lord like Moses, he did not say that he was Pharoah's son and he wanted to suffer with the children of Israel rather than living in luxury in Pharoah's palace. We need to have a heart for the service of God like Paul and Nehemiah. Jonah did not want to go to Ninveh and we do not want to witness the true gospel. The best place to practise self denial is by fasting and prayer. Time is short. The clock is ticking, seconds, minutes hours, days, weeks, months and years comes and goes, we are only a remnant, we need to wake up inspite of all the odds and be like Nehemiah in serving the Lord.
A remnant returned and they build the temple and the walls of Jerusalem, against all the odds. It was a remnant who served the Lord.  "So built we the wall; and all the wall was joined together unto the half thereof: for the people had a mind to work." (Ne 4:6 )