A Prophet is a man who is used by God to speak to His people. He simply speaks the Word of God.
A Priest speaks to God for the people.
Both were formal positions within the nation of Israel in OT times. The King of Israel, as a client nation of God, could not be placed in office unless chosen by God. The Prophet was the formal position through which the King was revealed to the people of Israel from God.
The obvious question would arise, how do we tell a true Prophet from a false prophet? A number of solutions were provided by God. One of which was to test the Prophet, since God is omniscient and always true, any Prophecy given by the Prophet could be tested against the Prophecies of Moses. If they conflicted, one could easily conclude the new prophecy was a fabrication from somebody other than God.
After the completion of the canon of Scripture, there are doctrinal arguments which assert the gift of Prophecy in the Church Age has ceased. (off top of my head they relate to some passages in Galatians and Ephesians, wherein Paul swears that by the Scripture itself, it was sufficient for every good work for every believer.) Run a google search for topics such as cessation of prophecy or cessationism.
Meanwhile in the Church Age, all believers receive a spiritual gift at the moment of salvation, not always the same gifts for different believers. Some might have a spiritual gift of pastor-teacher and other the gift of interpretation of tongues, others might have other spiritual gifts.
When faced with a spiritual message, a dilemma would occur for the Prophet, in that if he failed to deliver the message, the blood of a warning would fall on his head if he failed to warn the people of a calamity. Conversely, if the prophecy failed to occur, then he was guilty of false prophecy, which carried the same penalty as adultery, namely stoning to death. The work of the Holy Spirit glorifies the Son.
Thanks for a decent answer...
It would have been easy to kick me down the road, so to speak. I appreciate you all taking to time to give me some things to work on.