Mt. 13:1-23 The Parable of the Sower - God's Word is the seed (the Gospel; Rom. 1:16; 1 Cor. 15:3-4), and three categories of men are born again spiritually: the "stony ground" that bear no fruit due to persecution; the "weedy ground" that bear no fruit due to the cares of this world; and the "good ground" which bear various amounts of fruit. "Two thirds" are carnal.
Mt. 13:24-30; 36-43 The Parable of the Wheat and the Tares - Again, God's Word is planted, but the "seed of the enemy" is also planted. Both "crops" claim to be believers, but "most of the wheat acts like tares, and most of the tares act like wheat." You can't tell them apart!
Mt. 13:31-32 The Parable of the Mustard Seed - The Gospel, the "smallest of seeds," will grow into a mighty tree. It is so big, that the "fowls of the air" make their nests in it. The fowls represent Satan and his demonic forces (Compare: Mt. 13:4, 19; Eph. 6:12).
Mt. 13:33 The Parable of the Leaven - The word "leaven" appears in twenty verses in the Bible, and without exception, it represents some form of sin or corruption. Look especially at: Mt. 16:6, 11-12; 1 Cor. 5:6-8; Gal. 5:9!
Mt. 13:44 The Parable of the Hidden Treasure - Based upon the previous parables, I believe the treasure is "hidden" because, out of fear, it has covered; "its light is under a basket" (Mt. 5:14-16; 13:43).
Mt. 13:45-46 The Parable of the Pearl of Great Price - Again, the "pearl" is hidden, and the "merchant" does not say anything about "showing it off" to the world.
Mt. 13:47-50 The Parable of the Net - Notice the "net" contains both "good fish" and "bad fish." Like the Tares and the Wheat, they will be sorted out at the end.
Is the Kingdom of God good? Yes and no! Just make sure you are in it!