In ancient times, there were three different leadership roles, each with a different focus/task. The three were interconnected, each tasked with modeling a different part of God’s character and humanity’s connection with Him.
KING - Rulership
While he may have sat on the throne, Israel’s king was not an absolute ruler; rather, he was a “prince” (in Hebrew, nasi) who led the army that fought Israel’s enemies. The understanding was that they commanded Israel on God’s behalf and at His direction; the LORD was Israel’s true king, and as long as the human kings reflected His character, they remained on the throne.
The kings were also tasked with being the model of rulership for Israel; they were to model for Israel how to be good managers of whatever land/property was under their command, as well as how justice was to be administered.
PRIEST - Relationship
The most important (human) voice in religious matters was the high priest; he shared the responsibility for Israel’s spiritual well being – and their relationship with GOD – with all the other priests of Israel. Like the kings, they had great power over the people, and served as a picture of GOD to the nation.
The priests were different, however; their job was to teach Israel about relationship – portraying how a healthy relationship with GOD was lived out, being an example of how Israel should respect other people, and drawing them together as a community. When the priests were honest, so were the people; when the priests became corrupt (such as Eli and his sons), the morality of the nation suffered.
PROPHET - Righteousness
In Israel, prophets served a triple role as messengers, poets, and social critics of their time(s). It was their jobs to teach/portray righteousness (right-living) to the people.
A) As messengers, they received the Word of GOD and publicly proclaimed His will to the people. In this way, they kept Israel informed of GOD’s will.
B) As poets, they expressed His heart and words in beautiful verse; various prophets wrote at least 17 books of the Old Testament.
C) As social critics, they acted as the public conscience of Israelite society, calling people out when they did not act as GOD would desire and giving them the opportunity to repent of their ways. Prophets were sometimes gifted messages that doubled as visions of the future, whether in words alone or portrayed in dreams.
There were some who attempted to take on the role without having been called to it by GOD, but there was always a surefire way to tell a true prophet from a false one – if the foretelling came to pass, then it had been spoken by a true messenger of GOD; if it did not, then the one who spoke was revealed as a liar.
Three roles, three people
The three roles interacted in their leadership over Israel, and sometimes clashed as one went off-track and another stepped in to proclaim GOD’s truth to guide them back onto the right path.
There have been many people in the Bible who have filled at least one of these roles, but only three individuals have filled all of the leadership roles:
Moses – from the Ten Plagues until his death on Mount Nebo, Moses served as GOD’s chosen prophet; from Mount Sinai until his death, he served as GOD’s chosen ruler of the Israelite nation; and while Aaron was high priest, Moses would have helped model/regulate priestly activities in the Tabernacle.
Samuel – as a son of Levi, Samuel’s life calling was in service to GOD, and he was trained for it under Eli; after Eli’s death, Samuel served as a priest and ruler of Israel (as last of the judges); and from his younger days through old age, Samuel acted as a prophet of GOD, playing a special part in appointing the first of Israel’s kings.
Jesus – as Son of GOD, Jesus was/is destined to be the ultimate leader over Israel and the world; the three gifts of the Magi foretell/portray this: gold (a symbol of royalty and His kingship), frankincense (a symbol of prayer and His priesthood), and myrrh (a symbol of healing and His role as suffering prophet).