We see the Kingdom of God in operation repeatedly throughout the history of the nation of Israel, but perhaps no place more profound than in the book of Judges.
In the book of Judges, the people had no king other than the Lord, and each did according to his own desires. Repeatedly, the nation would believe for a while, and then their hearts would turn from the Lord and seek other things. And, the pattern is established, that, after crying out to the Lord, sometimes for many years, the Lord would turn, and hear their cries, and send them a deliverer, a judge.
It may be considered, thinking about the lifespan of these individuals, that perhaps God heard on the day they began to cry, and the deliver was conceived. And, through their continued persistence and increasing cries, the deliver was prepared. In the fervency and their need, the person was trained, and, at the outbreaking of their greatest need, he was brought forth.
But, let it be seen that without the poverty of Spirit as manifested by the contiual calling out, the individual would never have arrived.
Yet, whenever God moved, it was His Kingdom.
The people had not taken possession of the Kingdom. They had no access to the Spirit, only the prophets did. But, they experienced the Kingdom. The people, while they had faith to believe, could only believe through the word of the servants of the Most High.
Although the mysteries of the Kingdom would remain hidden for many years, God operated on the same basic principles. Faith, need, brokenness, caring for both the just and the unjust, and looking after them.
Consider even the story of Hagar. She was a slave-woman, and one that Abraham should have never slept with, yet, when she was driven from people, God heard her cries, and she called Him Yahweh Rohi, the Lord that sees me.