“Sanctify them in the truth; your word is truth.”
This verse is part of Jesus Christ’s high priestly prayer.
To become sanctified – to become holy as Christ is holy – requires the truth.
Where do we find the truth? The answer is right there – “your word is truth.” The word is all that’s revealed in the scriptures to us and the word is also Christ who is truth.
So, what is truth? Christ is the truth. John 14:6 “I am the way and the truth and the life. No one comes to the Father except through me.”
Want to know the truth? Get to know Christ and get to know His word, the Bible. This starts with simply reading it, the Bible.
Next? Pray and meditate on what you read. (meditate = spend time in reflection, thinking on what you read, it’s meaning and how it fits in with what is said elsewhere in the Bible)