John 1:9 ἦν τὸ φῶς τὸ ἀληθινόν, ὃ φωτίζει πάντα ἄνθρωπον, ἐρχόμενον εἰς τὸν κόσμον.
The true light that enlightens everyone was coming into the world.
Adjective: Nominative Singular Neuter

John 6:32 εἶπεν οὖν αὐτοῖς ὁ Ἰησοῦς· ἀμὴν ἀμὴν λέγω ὑμῖν, οὐ Μωϋσῆς ἔδωκεν / δέδωκεν ὑμῖν τὸν ἄρτον ἐκ τοῦ οὐρανοῦ, ἀλλ' ὁ πατήρ μου δίδωσιν ὑμῖν τὸν ἄρτον ἐκ τοῦ οὐρανοῦ τὸν ἀληθινόν·
Jesus therefore said to them, "Most certainly, I tell you, it wasn't Moses who gave you the bread out of heaven, but my Father gives you the true bread out of heaven.
Adjective: Accusative Singular Masculine

John 17:3 αὕτη δέ ἐστιν ἡ αἰώνιος ζωή ἵνα γινώσκωσιν σὲ τὸν μόνον ἀληθινὸν θεὸν καὶ ὃν ἀπέστειλας Ἰησοῦν Χριστόν.
This is eternal life, that they should know you, the only true God, and him whom you sent, Jesus Christ.
Adjective: Accusative Singular Masculine

1 John 2:8 πάλιν ἐντολὴν καινὴν γράφω ὑμῖν ὅ ἐστιν ἀληθὲς ἐν αὐτῷ καὶ ἐν ὑμῖν, ὅτι ἡ σκοτία παράγεται καὶ τὸ φῶς τὸ ἀληθινὸν ἤδη φαίνει.
Again, I write a new commandment to you, which is true in him and in you; because the darkness is passing away, and the true light already shines.
Adjective: Nominative Singular Neuter

1 John 5:20 οἴδαμεν δὲ ὅτι ὁ υἱὸς τοῦ θεοῦ ἥκει καὶ δέδωκεν ἡμῖν διάνοιαν ἵνα γινώσκομεν / γινώσκωμεν τὸν ἀληθινόν, καὶ ἐσμὲν ἐν τῷ ἀληθινῷ ἐν τῷ υἱῷ αὐτοῦ Ἰησοῦ Χριστῷ. οὗτός ἐστιν ὁ ἀληθινὸς θεὸς καὶ ζωὴ αἰώνιος.
We know that the Son of God has come, and has given us an understanding, that we know him who is true, and we are in him who is true, in his Son Jesus Christ. This is the true God, and eternal life.
Adjective: Accusative Singular Masculine