He put another parable before them, saying, “The kingdom of heaven is like a grain of mustard seed that a man took and sowed in his field. It is the smallest of all seeds, but when it has grown it is larger than all the garden plants and becomes a tree, so that the birds of the air come and make nests in its branches.” Matthew 13:31-32 (ESV)
There are varying opinions on the interpretation of this parable. One interpretation is based on observations from previous parables. Jesus is the man who sows the seed; which is the kingdom (Matthew 13:37), the field is the world (Matthew 13:38). Some commentators propose that mustard does not grow to be a tree but only a shrub. So, the growth of the mustard seed into a tree must signify something unnatural. Thus the kingdom of God started with meager beginnings (smallest of all seeds) and as it grew in became something “unnatural” or perverted through false doctrine, sinful practices and hypocrisy. The birds of the air are considered to be satanic spirits which have found a home in which to roost (Matthew 13:4; Mark 4:15).
This particular interpretation would leave us with this: The kingdom of heaven is like a grain of mustard seed which Jesus planted in the world. Though it was small and holy in the beginning it grew to be perverted, full of hypocrisy; something in which it was not intended. It is now so perverted or unnatural that Satan and his demons have made it a place to call home.
Though there could be some merit to this interpretation, it seems to render the kingdom of God as something that began holy but became perverted and demonic. It is difficult to imagine that Jesus had this in mind. There are perversions which may appear to be the kingdom of God. The apostle Paul wrote that there are false apostles and deceitful workers who transform themselves into apostles of Christ. Even Satan is transformed into an angel of light. (2 Corinthians 11:13, 14)
The true kingdom of God however is not perverted nor does it house evil things (Galatians 5:21). The true kingdom of God consists of righteousness, peace and joy in the Holy Spirit (Romans 14:17). The perversions are not the kingdom of God but are the kingdoms of this world; Babylon (Revelation 18:2). Jesus did not say in the parable that the birds were unclean nor does every reference that Jesus makes of birds deem them as unclean (Matthew 6:26; 8:20; Luke 12:24). Jesus was conveying the characteristics of the true kingdom not the characteristics of the perversion. The kingdom of God is not something that grows out of proportion or unnaturally but supernaturally (Matthew 12:28).
It seems a more logical (and maybe over simplified) interpretation would be that the kingdom of heaven (God) began, in this world, with humble beginnings (through Jesus coming as a baby). As it took root it began to supernaturally spread (Matthew 8:16; John 3:8) and will eventually permeate and overtake all other kingdoms of this world (Daniel 7:27; 1 Corinthians 15:24-27; Revelation 11:15). Every person who comes into the kingdom will find abundant provision and protection now and to its fullest in the future (Psalm 23; Revelation 7:17).
God has commissioned the church to make disciples of all nations (Matthew 28:19-20 ESV). To make disciples you must first make converts. Each time someone bows their knee to the Lordship of Jesus Christ the kingdom of God (his rule and reign) is extended in the earth (Acts 8:12). A new “bird” has found provision and protection. Each time someone is freed from demonic activity or healed from disease, the kingdom of God is extended (Matthew 9:35; 12:28). However, we will not experience the full measure of God’s kingdom until Jesus returns (2 Timothy 4:1, 18).
That’s why we praise him!