First we must ask the question is there truth? If there is no truth, then everything is a lie. Yet if there is no truth, there can be no lie. If there is no truth, nothing matters. We cannot believe anything or assert anything. Everything is arbitrary and meaningless. If there is no truth, the last several sentences are not true. If there is no truth, there is no knowledge at all. There must be truth or there is no way to have any sense of reality, being, or thought. The next question is the one Pontius Pilate asked while questioning Jesus, “What is truth (John 18:38)?” Truth has many aspects. Truth can be correct testimony – “Do you swear that the testimony you are about to give to be the truth, the whole truth, and nothing but the truth so help you God?” It can be honesty – “Did you chop down the cherry tree, George? I cannot tell a lie.” It can be facts and information, doctrine, or accurate perception – “Ain’t that the truth!”
However, in the greatest sense truth is an overarching principle, and in that sense it must be absolute. This is moral or spiritual truth. Some would argue that truth is relative to time and place. This violates the very nature of truth. We are not talking about personal, cultural, or societal beliefs. Those can change over time. That is because those are made by man, who is imperfect and susceptible to error. What may be “true” to one society or culture may not be “true” to the other. That does not make actual truth adaptable or relative. In the natural world this is impossible. Trees are made of wood. They have always been made of wood. They are made of wood in every part of the world. This truth is not changeable or relative. It is universal. Someone can come along and say, “Trees are not made of wood. They are made of carbon fiber.” They can make a very expensive fake tree out of carbon fiber, but that does not make the statement true. Truth by its very nature must be absolute or it cannot be true. There is only truth and lies. If something ceases to be true, it is a lie, and never was true in the first place (Rom 1:25, 1Jn 2:21). Circumstances may change, but truth does not. Another example is that the Bible teaches us to dress in modest apparel (1Tim 2:9). This is an unchanging principle which says we should dress to cover our nakedness, and that we should dress in a manner appropriate for a Christian. Styles of dress have changed over the years, and vary from place to place, but the principle of modesty applies in all places at all times.
When it comes to spiritual doctrine, there can only be one truth. Jesus did not start any denominations. Those were all started by men. He gave one message to His disciples, and they consistently preached that one message everywhere they went. Essentially that message is the death, burial, and resurrection of Jesus Christ. It is attested to by His miracles, His life, and the fulfillment of Biblical prophecy. It is applied to us through repentance, water baptism by immersion in the name of Jesus Christ for the remission of sins, and the gift of the Holy Ghost accompanied by the initial outward evidence of speaking with tongues (Acts 2:1-4, Acts 2:38-39, Acts 8:12-17, Acts 10:43-48, Acts 19:1-6, Acts 22:16, Rom 6:1-4, 1Cor 15:1-4, Col 2:8-12). Jesus Christ is the center of the message of the apostles and the whole Bible because He is the truth (Jn 1:14 & 17, Jn 8:40-46, Jn 14:6 & 16-26, Jn 18:37-38, Eph 4:21). The only way to know God is through knowing the truth of Jesus Christ (Jn 3:21, Jn 4:24). Any teaching that denies or diminishes this role of Jesus Christ is inherently false.
Truth cannot be relative because two opposing statements cannot both be true. There is no such thing as "That's your truth but it's not mine." Either Jesus Christ is who He said He is, or He is a liar; but He is not a liar. The liar is the one who denies who He said He is (Jn 8:55, 1Jn 2:22). No one is equal to Him (Is 40:25, Is 46:5). No alleged teacher or prophet that contradicts Him is telling the truth. Even angels must abide by His word (Gal 1:6-9). Jesus is not one of many. He is the only One. His word is the only way to know God and be saved. It is absolute (Jn 6:26-63, Acts 4:12).