The voice of him that crieth in the wilderness, Prepare ye the way of the Lord, make straight in the desert a highway for our God. ~ Isaiah 40:3

The New Testament reveals that Isaiah the prophet was speaking of John the Baptist in the text above.

In those days came John the Baptist, preaching in the wilderness of Judaea, And saying, Repent ye: for the kingdom of heaven is at hand. For this is he that was spoken of by the prophet Esaias (Isaiah), saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight. ~ Matthew 3:1-3 

Before the birth of John the Baptist, the angel Gabriel had appeared to his father, Zacharias, to inform him that he and his wife, Elisabeth, were going to have a child. Among other things, Gabriel announced the following concerning John the Baptist:

…thou shalt have joy and gladness; and many shall rejoice at his birth. And many of the children of Israel shall he turn to the Lord their God. And he shall go before him in the spirit and power of Elias, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord. ~ Luke 1:15-17

Notice that Gabriel says of John’s ministry, “he shall make a people ready for the Lord.” Keep in mind that this is a reference to those within Israel, for John the Baptist was sent to the people of Israel, to prepare them for the coming of Jesus.

Gabriel also declared that John would go forth in the spirit and power of Elijah.

This visitation from the angel Gabriel left Zacharias startled and bewildered in unbelief, and resulted in Zacharias being struck dumb (mute) because of his unbelief until after the birth of John (Luke 1:20). After his birth, when John was eight days old, Zacharias and his wife, Elisabeth, brought the young child to be circumcised. ~ Luke 1:59

Some of the people thought that the child should be named Zacharias after his father, but Elizabeth had told them that his name was to be John. So they enquired of Zacharias as to what the child’s name would be.

Zacharias then signaled for a writing table, and wrote, “His name is John.” The people were all amazed and Zacharias’s mouth was opened immediately, and his tongue loosed, and he spoke, and praised God. ~  Luke 1:63-64

Next we read the following:

And fear came on all that dwelt round about them: and all these sayings were noised abroad throughout all the hill country of Judaea. And all they that heard them laid them up in their hearts, saying, what manner of child shall this be! And the hand of the Lord was with him. ~ v.65-66

Luke then tells us that Zacharias was filled with the Holy Spirit, and prophesied the following:

Blessed be the Lord God of Israel; for he hath visited and redeemed his people, And hath raised up an horn of Salvation for us in the house of his servant David; As he spake by the mouth of his holy prophets, which have been since the world began: That we should be saved from our enemies, and from the hand of all that hate us; To perform the mercy promised to our fathers, and to remember his holy covenant; The oath which he sware to our father Abraham, That he would grant unto us, that we being delivered out of the hand of our enemies might serve him without fear, In holiness and righteousness before him, all the days of our life. And thou, child, shalt be called the prophet of the Highest: for thou shalt go before the face of the Lord to prepare his ways; To give knowledge of salvation unto his people by the remission of their sins, Through the tender mercy of our God; whereby the Dayspring on high hath visited us, To give light to them that sit in darkness and in the shadow of death, to guide our feet into the way of peace. ~ Luke 1:68-79

Then, in verse 80, Luke says of John the Baptist: “And the child grew, and waxed strong in spirit, and was in the deserts till the day of his shewing unto Israel.

John the Baptist was the messenger whom God sent to Israel to prepare them for the salvation he had promised to Israel. The specific reason that John came baptizing was to make the Messiah known to Israel!

This is he of whom I said, After me cometh a man which is preferred before me: for he was before me. And I knew him not: but that he should be made manifest to Israel, therefore am I come baptizing with water. ~ John 1:30-31

All the prophets before John had prophesied by the Spirit concerning the coming salvation in Christ. The apostle Peter tells us the prophets inquired and searched diligently, regarding the salvation and grace that was to come through Christ. ~ 1 Peter 1:10John the Baptist was the last of all the prophets which would testify of Christ to Israel, and according to Jesus, there was no prophet ever who was greater than John. While the other prophets had the honor of testifying of Christ, only John had the honor of introducing Christ. Again, John came baptizing for this one purpose: to reveal the Messiah to Israel! ~ John 1:29-34