THE URIM AND THUMMIM.

The Urim and Thummim are mysterious objects, possibly oracular stones, which were carried in the breastplate of the High Priest and used to divine the will of God.
It is thought that they represented contrasting ideas like light and darkness, yes and no, life and death, etc. They were shaken, or drawn out of the ephod. If each showed the same side, the answer was auspicious or inauspicious, according to the designation of each side, if different, no answer was forthcoming.
Thummim is a word derived from the consonantal root 't-m-n' meaning 'innocent,' while Urim derive from a root meaning 'light.' In consequence, the translation of the words, by taking them allegorically, mean 'Revelation of the Truth.'
In 1Samuel 14 is regarded as the key to understanding the meaning of the words. The passage describes an attempt to identify a sinner via divination, by repeatedly splitting the people in two groups and identifying which group contains the sinner. This imply that the purpose of the Urim and Thummim was an ordeal to confirm or deny suspected guilt. If the Urim was selected it meant guilt, while selection of the Thummim would mean innocent. In order for the Urim and Thummim to give an answer, it was first necessary for it to be loud enough for the individual to stand facing the fully dresses high priest, and vocalize the question briefly and in a simple way, though it wasn't necessary for it to be loud.
A passage of the Book of Samuel mentions 3 methods of divine communication: Dreams, Prophets, and the Urim and Thummim. They had to rest within the breastplate of the high preast mediating between God and mankind.
Dreams and Prophets are also mentioned copiously in Assyrian and Babylonian literature, and such literature also mentions 'Tablets of Destiny.' They also had to rest on the breast of deities mediating between the other gods or entities and mankind in order to function. Marduk was said to have put his seal on the 'Tablets of Destiny,' and came into use when the fate of a king or nation was concerned.
The 1st reference to Urim and Thummim in the Scriptures is the description in the Book of Exodus concerning the high priest's vestments. The chronological earliest passage mentioning them is in the Book of Hosea, one of the Books of the Hebrew Bible, where it is implied, by reference to the Ephod, that Urim and Thummim were fundamental elements in the Israelite faith.
Hosea was a prophet during a dark and melancholic era of Israel's history, the Northern Kingdom's decline and fall in the 8th BC. The apostasy of people was rampant, having turned away from God in order to serve other entities. The kings, their aristocratic supporters, and the priests had led the people away from the Law of God. Other sins followed, including homicide, perjury, theft, and sexual sin.
Hosea declared that unless they repent of these gross scenario of sins, God will allow their nation to be destroyed, and the people be taken into captivity by Assyria. God's unending love towards his people and His agony towards Israel's betrayal is expressed in this prophesy. It is summed up in this verse: "I have been the Lord your God ever since the land of Egypt; you know no God but Me, and besides Me there is no Saviour." (Hosea 13).
In a passage from the the Book of Ezra which overlaps with the Book of Nehemiah, it is mentioned that individuals who were unable to prove, after the Babylonian captivity had ended, that they were descended from the priesthood before the captivity began, were required to wait until divine priests in possession of Urim and Thummim were discovered. In that specific way it is understood that the divine priest could use again the Urim and Thummim to determine God's will this particular situation, because the heart of the priest works in direct and divine connection with the will of God.
With the coming of Christ, the representation of the Urim and Thummim was taken by Him. He is now the divine connection and we as his followers need to be in constant connection with his divine heart and mind.
In 1 Samuel 28 it is stated that a definite answer was not always obtainable, so it is not so simple to gain a divine connection, and do not take the understanding that the connection is like a simple tossing of two stones in the ground and gaining it.