Jesus said, "My kingdom is not of this world." Pilate said, "So you are a king?" Jesus answered, "You say rightly that I am a king. For this cause I was born and for this cause I have come into the world that I bear witness to the truth. Everyone who is of the truth listens to my voice." Pilate said, "What is truth?" Then he went back outside and told the Jews, "I find no guilt in him." John 18:36-38
What is truth? That is the million dollar question.
I find it interesting that Pilate did not wait to hear Jesus' answer to his question.
Jesus said, "I am the way, the truth, and the life. No one comes to the Father except through me." John 14:6
Jesus is the truth, and Jesus bears witness to the truth. So he is the truth, and he's also telling the truth.
Bears witness (verb) vouch for, attest, confirm, testify, prove, give testimony, to show that something exists.
Truth (noun) a verified or undisputable fact; reality; honesty.
Thesaurus synonym for truth is gospel.
Gospel (noun) the teachings of Jesus and the apostles; the story of Christ's life and teachings, especially as contained in the first four books of the New Testament, namely Matthew, Mark, Luke, and John; something accepted as infallible truth.
Infallible (adjective) incapable of error.
Jesus said he is the truth. Just like God says, "I am."
Then Jesus says he bears witness to the truth. Jesus always points to God the Father.
So you could replace the truth with God...Everyone who is of God hears my voice.
"I am the door of the sheep...The thief comes only to steal and kill and destroy. I came that they may have life and have it abundantly. I am the good shepherd. The good shepherd lays down his life for the sheep." John 10:7-15
The sheep know their Shepherd's voice. John 10:27
Jesus said, "If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free...so if the Son sets you free, you will be free indeed." John 8:31-36
Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things. What you have learned and received and heard and seen in me...practice these things, and the God of peace will be with you." Phil. 4:8-9