“Then the righteous will shine like the sun in the kingdom of their Father. “ (Matthew 13:43)

The righteous are the people of the kingdom of heaven.

What Jesus sows in the world are good seeds and they are the Words of God.
The enemies of Jesus will wait till men are asleep and then sow, among the wheat, weeds, i.e. evil.

Wheat and weeds will grow together until the time of harvest when they will be treated separately: weeds will be thrown into furnaces while the righteous will shine like the sun in the kingdom of their Father.   

During the days while we are alive, we still have the freedom to choose. 
The Parable of the Lost Son tells us clearly that the Father is forever waiting for our conversion.

“I shall get up and go to my father and I shall say to him: ‘Father, I have sinned against heaven and against you. I no longer deserve to be called your son; treat me as you would treat one of your hired workers.' So he got up and went to his father.

"While he was still a long way off, his father caught sight of him, and was filled with compassion. He ran to his son, embraced him and kissed him.

 "His son said to him, 'Father, I have sinned against heaven and against you. I no longer deserve to be called your son.'

"But his father ordered his servants, 'Quickly bring the finest robe and put it on him; put a ring on his finger and sandals on his feet. Take the fattest calf and slaughter it. The let us celebrate with a feast because this son of mine was dead, and has come to life again; he was lost and has been found.' Then the celebration began.” (Luke 15:18-24) What Jesus said to the one of the criminals who were crucified with him is the best example: “Amen, I say to you, today you will be with me in Paradise.” (Luke 23:43)