The English word prophet in the Old Testament comes from the Hebrew word “nabiy” which means “spokesman” or “speaker”. The Greek word for prophet is “prophētēs”, which can mean “one who speaks forth” or “advocate.” Prophets are also called “seers,” because of their spiritual insight or their ability to “see” the future, as directed by God.
John the Baptist
If you asked most people if John the Baptist was a prophet they would probably say No. They would say that he was the person that the prophets Isaiah and Malachi Isaiah were talking about when they said;
Isaiah 40:3 (NLT)3 Listen! It’s the voice of someone shouting, “Clear the way through the wilderness for the LORD! Make a straight highway through the wasteland for our God!
And Malachi when he said
Malachi 3:1 (NLT) “Look! I am sending my messenger, and he will prepare the way before me. Then the Lord you are seeking will suddenly come to his Temple. The messenger of the covenant, whom you look for so eagerly, is surely coming,” says the LORD of Heaven’s Armies.
However Jesus said that John the Baptist was a prophet.
Matthew 11:9-11 (NLT)9 Were you looking for a prophet? Yes, and he is more than a prophet.10 John is the man to whom the Scriptures refer when they say, ‘Look, I am sending my messenger ahead of you, and he will prepare your way before you.’11 “I tell you the truth, of all who have ever lived, none is greater than John the Baptist. Yet even the least person in the Kingdom of Heaven is greater than he is! (emphasis mine)
John the Baptist was, in fact, the last of the Old Testament prophets.
Luke 1:17 (NLT) He will be a man with the spirit and power of Elijah. He will prepare the people for the coming of the Lord. He will turn the hearts of the fathers to their children, and he will cause those who are rebellious to accept the wisdom of the godly.”
He was the prophet where the Old Testament overlapped and ran into the New Testament.
John didn’t perform any miracles or write and scripture yet Jesus called him the greatest prophet because he was the forerunner of the Messiah, preparing the people for Jesus.
Mark 1:2-4 (NLT)2 just as the prophet Isaiah had written: “Look, I am sending my messenger ahead of you, and he will prepare your way.3 He is a voice shouting in the wilderness, ‘Prepare the way for the LORD’s coming! Clear the road for him!’”
4 This messenger was John the Baptist. He was in the wilderness and preached that people should be baptized to show that they had turned to God to receive forgiveness for their sins.
The reason I say that John the Baptist was the last Old Testament prophet because the old covenant was still in place when he lived a preached. The Old Testament covenant was not done away with until the death of Christ.
Hebrews 8:13 (NLT) When God speaks of a “new” covenant, it means he has made the first one obsolete. It is now out of date and will soon disappear.
Hebrews 9:15 (NLT)15 That is why he is the one who mediates a new covenant between God and people, so that all who are called can receive the eternal inheritance God has promised them. For Christ died to set them free from the penalty of the sins they had committed under that first covenant.