"the voice of one
calling in the wilderness"
"...make straight in the desert a highway for our God."
When God was about to send His Son into the world to establish His Kingdom, He sent a forerunner before Him to prepare the way. John the Baptizer announced the coming King and urged people then to repent of sins and be baptized to make ready for Jesus.
In a similar way, the church has been sent into the world to announce the established reign of King Jesus today. The territory that needs prepared for the Lord lies in the hearts of men and women. We must all have hearts ready to receive Him.