What is truth? It is a good question when people think that they can believe anything they want and "be okay" But there is absolute unchanging truth in God's Word.
JESUS is TRUTH. John 14:6 "Jesus said to him, I am the way, the truth, and the life: no man comes to the Father but through me."
The GOSPEL is TRUTH. Ephesians 1:13 "In Him, you also, after listening to the message of truth, the gospel of your salvation--having believed, you were sealed in Him with the Holy Spirit of promise."
GOD'S WORD is TRUTH John 17:17 "Sanctify (set-apsrt) them in the truth; Thy Word IS truth."
The HOLY SPIRIT leads us to TRUTH. John 16:13 "But when He, the Spirit of Truth, comes, He will guide you into all truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose what is to come."
John 8:32 "You shall know the TRUTH and the TRUTH shall make you free."
John 8:36 "So if the Son shall make you free, you shall be free indeed."