Is truth relative

No, objective truth is not relative. If someone claims this, it is not truth. Subjective matters are not truth because unregenerate autonomy is subject to arbitrary scrutiny, and is not confirmed by empirical means. Conventions and consensuses are not truth either, this is proven when the universality of abstract entities are appealed to. For example utilitarianism appeals to the greatest good for the many, and is not truth, because pragmatism doesn't the concerns raised by metaphysics. Only the Christian worldview and its proclamation to the foundations of truth is to the impossibility of the contrary. No other worldview can account for abstract entities, and their universal application and invariant character. 2 Corinthians 13:8 "For we can do nothing against the truth, but for the truth."