(Pro 14:5 KJV) A faithful witness will not lie: but a false witness will utter lies.
Notice what we are to be “faithful” (529) to: Truth. I remember a song by the Beach Boys that was “Be True to your School”. We often have family members or friends who think we are to stick by them even when they are wrong. By that they mean lie for them or get violent for them. That is not our calling.
One of the basic differences between the world and those who are real followers of Jesus is that we serve a God of objective absolutes. He is a person. He makes allowances. He is patient. We could go on in that way but a basic truth that goes along with that is He is immutable, unchanging. Truth does not change and be are to be faithful to the truth.
So? Our world is subjective. For most people truth is what fits their agenda. For us truth is what is.