All Nations Are Called to Faith in Christ — Indications in the New Testament
Christ sends the apostles to preach the Gospel to all nations, tribes, speaking any language, to the whole world:
“Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age. Amen” (Matt. 28:19-20)
“Through Him we have received grace and apostleship for obedience to the faith among all nations for His name” (Rom. 1:5)
“Now to Him who is able to establish you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery kept secret since the world began but now made manifest, and by the prophetic Scriptures made known to all nations, according to the commandment of the everlasting God, for obedience to the faith” (Rom. 16:25-26)
“And this gospel of the kingdom will be preached in all the world as a witness to all the nations, and then the end will come” (Matt. 24:14)
“Then I saw another angel flying in the midst of heaven, having the everlasting gospel to preach to those who dwell on the earth — to every nation, tribe, tongue, and people” (Rev. 14:6)
All Nations Are Called to Faith in Christ — Indications in the Old Testament
The promise to Abraham that in his seed (through one of his descendants) all nations would be blessed:
“In your seed all the nations of the earth shall be blessed, because you have obeyed My voice” (Gen. 22:18)
Prophecies that all nations will turn to the true God:
“All nations whom You have made shall come and worship before You, O Lord, and shall glorify Your name” (Ps. 86:9)
“Yes, all kings shall fall down before Him; all nations shall serve Him” (Ps. 72:11)
“His name shall endure forever; His name shall continue as long as the sun. And men shall be blessed in Him; all nations shall call Him blessed” (Ps. 72:17)
“Praise the LORD, all you Gentiles! Laud Him, all you peoples!” (Ps. 117:1)
“It shall be that I will gather all nations and tongues; and they shall come and see My glory. I will set a sign among them; and those among them who escape I will send to the nations: to Tarshish and Pul and Lud, who draw the bow, and Tubal and Javan, to the coastlands afar off who have not heard My fame nor seen My glory. And they shall declare My glory among the Gentiles. Then they shall bring all your brethren for an offering to the LORD out of all nations, on horses and in chariots and in litters, on mules and on camels, to My holy mountain Jerusalem, says the LORD, as the children of Israel bring an offering in a clean vessel into the house of the LORD. And I will also take some of them for priests and Levites, says the LORD” (Is. 66:18-21)
“Look to Me, and be saved, all you ends of the earth! For I am God, and there is no other” (Is. 45:22)
“I will also give You as a light to the Gentiles, that You should be My salvation to the ends of the earth” (Is. 49:6)
“That Your way may be known on earth, Your salvation among all nations” (Ps. 67:2)
“Then to Him was given dominion and glory and a kingdom, that all peoples, nations, and languages should serve Him. His dominion is an everlasting dominion, which shall not pass away, and His kingdom the one which shall not be destroyed” (Dan. 7:14)
“Declare His glory among the nations, His wonders among all peoples” (1 Chr. 16:24)
“that all the peoples of the earth may know that the LORD is God; there is no other” (1 Kin. 8:60)
“and I will shake all nations, and they shall come to the Desire of All Nations, and I will fill this temple with glory, says the LORD of hosts” (Hag. 2:7)
“For as the earth brings forth its bud, as the garden causes the things that are sown in it to spring forth, so the Lord GOD will cause righteousness and praise to spring forth before all the nations” (Is. 61:11)
The Faiths of Other Nations Are Not Saving
The apostolic faith in Jesus Christ is saving. The faiths of other nations are not saving:
“who [God] in bygone generations allowed all nations to walk in their own ways” (Act. 14:16)
More: the gods of other nations are not gods
At the same time, the apostolic faith in Jesus Christ and salvation by this faith are open to all people without exception.