-- true worshippers shall worship the Father in spirit and in truth --- John 4:23
-- God is a Spirit, and they that worship him must worship him in spirit and truth --- John 4:24
-- you shall know the truth and the truth shall make you free --- John 8:32
-- another Comforter, the Spirit of truth, who dwells with you and in you --- John 14:16-17
-- the Comforter, the Spirit of truth --- John 15:26
-- the Spirit of truth will guide you into all truth --- John 16:13
-- the wrath of God is against all who hold the truth in unrighteousness --- Romans 1:18
-- the word of truth, the gospel of your salvation --- Ephesians 1:13
-- the fruit of the Spirit is in all goodness and righteousness and truth --- Ephesians 5:9

John 4:23-24 KJV
[23] But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him. [24] God is a Spirit: and they that worship him must worship him in spirit and in truth.

John 8:32 KJV
[32] And ye shall know the truth, and the truth shall make you free.

John 14:15-17 KJV
[15] If ye love me, keep my commandments. [16] And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; [17] Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.

John 15:26 KJV
[26] But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:

John 16:13 KJV
[13] Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.

Romans 1:18 KJV
[18] For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;

Ephesians 1:13 KJV
[13] In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation in whom also after that ye believed, ye were sealed with that holy Spirit of promise,

Ephesians 5:9 KJV
[9] (For the fruit of the Spirit is in all goodness and righteousness and truth;)

John 14:15 begins with "If," which implies there is some work to be done in order to show our love for God.

John 14:15 KJV
[15] If ye love me, keep my commandments.

Those who keep his commandments will be given the Comforter, the Spirit of truth, who will guide them into all truth.

John 16:13 KJV
[13] Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.