Answer
The specific phrase highway of holiness is found only once in Scripture, in Isaiah 35. In this chapter, God promises that, in the future, the land of Israel will be blessed with fertility and “the desert shall rejoice and blossom as the rose” (verse 2). Isaiah’s prophecy of the messianic kingdom also encourages the weak and fearful to be strong, for God will come with vengeance to save the long-oppressed people of Israel (verses 3–4). There will be gladness and shouts of joy when the new, restored Zion will see God’s glory, experience His presence, and be guided and protected by Him.
At the time the kingdom is established, “a highway will be there; it will be called the Way of Holiness” (Isaiah 35:8). The highway of holiness does not need to be a literal highway; the point of the prophecy is that God will remove all obstacles and “smooth the way” for His people, enabling them to access the blessings of the kingdom. Some point to the fulfillment of this prophecy as the Jews’ return from captivity in Babylon and Persia. But the language of Isaiah 35 gives it a broader context, including physical healing and environmental blessings (verses 5–7). The highway of holiness could also be seen to refer to the Way that is Christ (see John 14:6), the way of sovereign grace that redeems us from sin.
The highway of holiness has three important characteristics. The first is found in Isaiah 35:8: “It will be for those who walk on that Way. The unclean will not journey on it; wicked fools will not go about on it.” The highway of holiness is a place of holiness. It is reserved for those who are righteous in God’s sight. No one entering the kingdom will be foolish or sinful. Christ alone provides the way of holiness, having exchanged His perfect righteousness for our sin (2 Corinthians 5:21). His righteousness is imputed to us, enabling us to be holy, even as He is holy. The highway is reserved for His people alone.
Second, the highway of holiness is a place of safety, reserved for the redeemed of the Lord. “No lion will be there, nor any ravenous beast; they will not be found there. But only the redeemed will walk there, and those the Lord has rescued will return” (Isaiah 35:9–10). This is indicative of the safety and security God’s people will experience on the highway. No wicked persons, symbolized by lions and ravenous beasts, will be allowed on the highway. The redeemed of the Lord will walk there in peace and safety.
Third, the highway of holiness will be a place of joy: “They will enter Zion with singing; everlasting joy will crown their heads. Gladness and joy will overtake them, and sorrow and sighing will flee away” (Isaiah 35:10). Just as the ransomed captives would return joyfully from Babylon, all the redeemed of the Lord will enter the millennial kingdom rejoicing.
Isaiah’s mention of a “highway” occurs again in Isaiah 40:3, referring to the first advent of the Messiah: “A voice of one calling: ‘In the wilderness prepare the way for the Lord; make straight in the desert a highway for our God.’” This prophecy was fulfilled by John the Baptist (see Matthew 3:3).