To the serious student of God’s Word, the parables produce one of the strongest evidences, that in the mind of Christ, the kingdom of God and the Gospel (or His Church) was one and the same.  The parables of Christ simply do not fit the concept of a physical kingdom here on earth.
That is not to say that his audiences - and yes, even his apostles, refused to grasp the spiritual nature of God’s kingdom or Christianity.  
In Matthew 13:10-11 Jesus explains that the purpose of the parables was "to know the mysteries of the kingdom of heaven.”  They are often introduced with the formula, "the kingdom of heaven or the kingdom of God is likened . . .” The classic definition of a parable is that it is an earthy story with a heavenly or spiritual meaning.  These mysteries or secrets reveal how the gospel works in the Christian age.
In the Parable of the Sower (Matthew 13:3-8; 18-23), we learn how the word (Mark 4:13) of God or the seed of the kingdom is received in the hearts of men.  Those that fell on the road or path heard the word but did not understand.  Those that fell among the stones hear the gospel and with joy receive it but when tribulation or persecution comes, because of the word, they fall away.  Those that fell among thorns receive the word, or seed of the kingdom, but the cares of  this world  and the deceitfulness of riches choke the word, and it becomes unfruitful.  However, 
he that hears  the word and understands the word or gospel is he that bears fruit.
The Parable of the Tares (Matthew 13:24-30; 37-43) is another lesson on preaching the gospel.  The wheat (Christians) and the tares (pompano) are to continue together until the Judgment Day.  How different from those Jihadists that insist on killing us infidels because we believe Jesus is God’s only begotten son (John 3:16).
The Parables of the Mustard Seed and Leaven (Matthew 13:31-33)point out aspects of the growth of the kingdom of heaven or the church in the early days of its existence.  Truly the leaven of Christianity was the basis of Western Civilization.  It is a crying shame that too many in America are rejecting that which produced our greatness and strengthened our uniqueness. 
In our review of this classical chapter on the parables and the Kingdom of Heaven, we note the following observations:

1. They do not fit the normal concept of an earthly kingdom with its carnal pomp and

2. They do reflect the early preaching and teaching of the New Testament church and the
spread of the Gospel as Jesus stated to the apostles prior to his ascension, "ye shall be
witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the
uttermost part of  the earth” (Acts 1:8).

Dale I. Royal
Elk City OK