The parables found in Matthew 13 are referred to as the parables of the kingdom of heaven (or of God). To be more specific, they are parables concerning the mystery or mysteries of the kingdom of heaven. (Mat 13:11; Mark 4:11) In essence, the mystery is the fact that the kingdom of God was inaugurated by Jesus at His first coming (Mat 3:2, 4:17, 12:28), and will be consummated at His second coming at the end of the age. (Mat 25:31-34)
The Jews anticipated one coming when Messiah would destroy their enemies and establish His kingdom upon the earth. It was probably because John the Baptist did not understand this mystery that he had doubts about the identity of Jesus which are reflected in his question, “Are You the Coming One, or do we look for another?” (Mat 11:2-3, cf. 13:16-17) John, like so many others, was looking for God’s wrath to be poured out on the ungodly at Messiah’s coming into His kingdom. (Mat 3:1-12)
The Parable of the Wheat and the Tares indicate a period of time between Christ’s first and second coming, or in other words, between the inauguration and the consummation of the kingdom when the godly and ungodly live side by side (Mat 13:24-30, 36-43). At the end of the age just before Christ establishes the kingdom of God on the earth, the tares (the wicked or sons of the wicked one) will be cast into hell. The wheat (the righteous or the sons of the kingdom) will inherit the kingdom of God, and forever live in the presence of God.