Isaiah 2:3

And many people shall go and say, in encouraging one another to seek the truth of the Gospel, Come ye and let us go up to the mountain of the Lord, to the house of the God of Jacob, to become members of the true Church, such zeal in coming and inviting others being a sign of real conversion; and He will teach us of His ways, literally, "out of His ways," so that the instruction will be most thorough, and we will walk in His paths, in the willing obedience of faith; for out of Zion, from the midst of God's holy congregation, shall go forth the Law, the word here designating the law of the New Covenant, the Gospel of God's mercy, and the Word of the Lord, of Jehovah, the God of grace, from Jerusalem. This explains the manner in which the Gentiles come to the city of God, to His holy Church, namely, by and through the preaching of the Gospel, which is brought to them and accepted by them.