"Since the day that your fathers came out of the land of Egypt until this day, I have even sent to you all My servants the prophets, daily rising up early and sending them" (Jeremiah 7:25).
"Surely the Lord GOD does nothing, unless He reveals His secret to His servants the prophets." (Amos 3:7).

God Spoke In Various Ways
Moses	Law
Wise Men	Counsel
Priests	Teaching of Law
Psalmists	Poetry
Prophets	Word

Before the Son of God became flesh, the Lord God spoke to men "at various times and in various ways" (Hebrews 1:1). He revealed Himself through Moses, the lawgiver, who delivered the law (Nehemiah 9:13-14). He advised through wise men, who gave counsel (Proverbs 1:1-6). He taught through priests, who were the teachers and interpreters of the law (Leviticus 10:8-11). He spoke by psalmists, who gave to Israel its inspired poetry (2 Samuel 23:1-2) and through prophets, the inspired preachers of His word (Amos 3:7-8).

"According to the uniform teaching of the Bible the prophet is a speaker of or for God. His words are not the production of his own spirit, but come from a higher source" (ISBE). When God commanded Moses and Aaron to go to Pharaoh, Aaron was to be "as a mouth," that is a "spokesman" for Moses, whereas Moses was to be "as God" to Aaron (Exodus 4:15-16). When the command was repeated, Aaron was called a "prophet," while Moses was "as God" (Exodus 7:1-2). Thus, the prophets of God, who wrote the Bible, were God's mouths or spokesmen.

Balaam was a prophet of the Lord (2 Peter 2:15-16). But though King Balak of Moab promised him a house full of silver and gold to curse Israel, and the prophet coveted the money, rather than cursing Israel, he blessed them four times (Numbers chapters 22 - 24; Jude verse 11), because he could only speak the words God put in his mouth (Numbers 22:38).

Prophets did sometimes foretell the future (cf. Deuteronomy 18:21-22), but the primary function of a prophet was to preach to the people the word God revealed to them (Jeremiah 7:1-3,25).

Though the Lord had prophets at least from the days of Abraham (Genesis 20:7), and Moses was a prophet in a class shared only with Christ (Deuteronomy 34:10-12; 18:18-19; Acts 3:19-23), the age of the prophets began with Samuel (Acts 3:24).

Prophets in Israel were first called "seers" (1 Samuel 9:9). A prophet was also designated as a "man of God" (1 Samuel 9:6), as a preacher is in the New Testament (1 Timothy 6:11). In seventeen Old Testament passages the prophets of the Lord are called His "servants the prophets."

The Lord worked mighty miracles through Elijah and Elisha to try to turn Israel from the Baal worship during the days of Ahab (1 Kings 17 - 2 Kings 13), and Elijah appeared with Moses and Christ on the Mount of Transfiguration (Matthew 17:1-3), but these prophets wrote no books. There were other well known Nonliterary Prophets, such as Nathan who served the Lord during the reign of David.

There are two groups of Literary Prophets, those who wrote inspired books that belong to the Old Testament canon. These are the Major Prophets - Isaiah, Jeremiah, Ezekiel, and Daniel, and the Minor Prophets - Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, and Malachi. This is not a difference in importance but in length of books. The four Major Prophets wrote longer books; the twelve Minor Prophets wrote shorter.

Their primary function to their own generation was to preach the word of the Lord. Much of their message pertains to the ancient society in which they lived.

But they have great value to us. Though we live under the New Testament rather than the Old, the principles of faith and righteousness preached by the prophets of old are timeless. "He has shown you, O man, what is good; and what does the LORD require of you but to do justly, to love mercy, and to walk humbly with your God?" (Micah 6:8) And of at least equal importance, "Yes, and all the prophets, from Samuel and those who follow, as many as have spoken, have also foretold" Christ, His kingdom, and His salvation (Acts 3:24).