Leighton Flowers refers to Luke 2:32 as a means of how people can come to know God, specifically Jesus, as a way that God provides to people Salvation. Let’s look at the verse and put some context into it.

Luke 2:32 (ESV)

³²  a light for revelation to the Gentiles, and for glory to your people Israel.”

We will start with some early commentaries on what Luke 2:32 means:

Ellicott’s Commentary for English Readers:

To lighten the Gentiles.—Literally, for a revelation to the Gentiles.The idea is strictly that of the withdrawal of the “veil spread over all nations” of Isaiah 25:7.

Barnes’ Notes on the Bible:

A light to lighten the Gentiles – This is in accordance with the prophecies in the Old Testament, Isaiah 49; Isaiah 9:6-7; Psalm 98:3; Malachi 4:2. The Gentiles are represented as sitting in darkness that is, in ignorance and sin. Christ is a “light” to them, as by him they will be made acquainted with the character of the true God, his law, and the plan of redemption. As the darkness rolls away when the sun rises, so ignorance and error flee away when Jesus gives light to the mind. Nations shall come to his light, and kings to the brightness of his rising, Isaiah 60:3.

Expositor’s Greek Testament:

Luke 2:32. φῶς εἰς ἀ. ἐ.: the Gentiles are to be more than spectators, even sharers in the salvation, which is represented under the twofold aspect of a light and a glory.—φῶς and δόξαν may be taken in apposition with ὃ as objects of ἡτοίμασας: salvation prepared or provided in the form of a light for the Gentiles, and a glory for Israel. Universalism here, but not of the pronounced type of Lk. (Holtz., H. C.), rather such as is found even in O. T. prophets.

Calvin’s Commentaries:

A light for revelation [198] means for enlightening the Gentiles Hence we infer, that men are by nature destitute of light, till Christ, “the Sun of Righteousness,” (Malachi 4:2,) shine upon them. With regard to Israel, though God had bestowed upon him distinguished honor, yet all his glory rests on this single article, that a Redeemer had been promised to him.

Are you seeing a trend here? This is not referring to people getting saved today by being granted some light and revelation to understand God. For we are already given knowledge enough to have no excuse for not obeying God. (Romans 1:18 (ESV)

¹⁸ For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth.)

Rather, this is a prophecy being fulfilled from all throughout Scriptures.

Isaiah 9:2 (ESV)

²  The people who walked in darkness have seen a great light; those who dwelt in a land of deep darkness, on them has light shone.

Isaiah 42:6 (ESV)

⁶  “I am the Lord; I have called you in righteousness; I will take you by the hand and keep you; I will give you as a covenant for the people, a light for the nations,

Isaiah 60:1–3 (ESV)

60 Arise, shine, for your light has come, and the glory of the Lord has risen upon you. ²  For behold, darkness shall cover the earth, and thick darkness the peoples; but the Lord will arise upon you, and his glory will be seen upon you. ³  And nations shall come to your light, and kings to the brightness of your rising.

Dr. Flowers is taking a verse out of context and applying it as if it pertains for today when in context, the verse is referring to an Old Testament prophecy which has been fulfilled.

How were the Old Testament Saints saved? By the same way we are. By Faith.

For what does the Scripture say? “And Abraham believed God, and it was reckoned to him as righteousness.” ⁴Now to the one who works, his wage is not reckoned as a favor, but as what is due. ⁵But to the one who does not work, but believes in Him who justifies the ungodly, his faith is reckoned as righteousness, ⁶just as David also speaks of the blessing upon the man to whom God reckons righteousness apart from works: ⁷“Blessed are those whose lawless deeds have been forgiven, and whose sins have been covered. ⁸“Blessed is the man whose sin the Lord will not take into account” (Rom. 4:3-8).

They believed God. They were looking forward to the coming Messiah. They were given this Light concerning this Christ who will take their sins away. Today, men are not enlightened by special revelation if they are born on a lone island with no missionaries in sight. They are given enough knowledge of God through His attributes to know that lying is a sin. Murder is wrong. Adultery is not tolerated by God. Mankind knows and is aware of God’s existence through Creation and through one’s conscience. But for one to be saved, genuinely, it is only by the Gospel.

Romans 1:16 (ESV)

¹⁶ For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek.

And what is that Gospel?

1 Corinthians 15:1–4 (ESV)

15 Now I would remind you, brothers, of the gospel I preached to you, which you received, in which you stand, ² and by which you are being saved, if you hold fast to the word I preached to you—unless you believed in vain.

³ For I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, ⁴ that he was buried, that he was raised on the third day in accordance with the Scriptures, 

-John Wilkinson, Atomicglue