Had Israel been true to her trust, all the nations of earth would have shared in her blessings. But the hearts of those to whom had been entrusted a knowledge of saving truth, were untouched by the needs of those around them. As God’s purpose was lost sight of, the heathen came to be looked upon as beyond the pale of His mercy. The light of truth was withheld, and darkness prevailed. The nations were overspread with a veil of ignorance; the love of God was little known; error and superstition flourished.
Such was the prospect that greeted Isaiah when he was called to the prophetic mission; yet he was not discouraged, for ringing in his ears was the triumphal chorus of the angels surrounding the throne of God, “The whole earth is full of His glory.” Isaiah 6:3. And his faith was strengthened by visions of glorious conquests by the church of God, when “the earth shall be full of the knowledge of the Lord, as the waters cover the sea.” Isaiah 11:9. “The face of the covering cast over all people, and the veil that is spread over all nations,” was finally to be destroyed. Isaiah 25:7. The Spirit of God was to be poured out upon all flesh. Those who hunger and thirst after righteousness were to be numbered among the Israel of God. “They shall spring up as among the grass, as willows by the watercourses,” said the prophet. “One shall say, I am the Lord’s; and another shall call himself by the name of Jacob; and another shall subscribe with his hand unto the Lord, and surname himself by the name of Israel.” Isaiah 44:4, 5.
To the prophet was given a revelation of the beneficent design of God in scattering impenitent Judah among the nations of earth. “My people shall know My name,” the Lord declared; “they shall know in that day that I am He that doth speak.” Isaiah 52:6. And not only were they themselves to learn the lesson of obedience and trust; in their places of exile they were also to impart to others a knowledge of the living God. Many from among the sons of the strangers were to learn to love Him as their Creator and their Redeemer; they were to begin the observance of His holy Sabbath day as a memorial of His creative power; and when He should make “bare His holy arm in the eyes of all the nations,” to deliver His people from captivity, “all the ends of the earth” should see of the salvation of God. Verse 10. Many of these converts from heathenism would wish to unite themselves fully with the Israelites and accompany them on the return journey to Judea. None of these were to say, “The Lord hath utterly separated me from His people” (Isaiah 56:3), for the word of God through His prophet to those who should yield themselves to Him and observe His law was that they should thenceforth be numbered among spiritual Israel–His church on earth.
Prophets and Kings, pp.371-372.