The fact that there is Truth implies that anything conflicting with the Truth is at least error and may in fact be lie.
Jesus said "I am the Truth" in .
➛ impuning much of the theology of the Jews and
➛ identifying Himself as greater than the HighPriest
➛ identiying Himself as THE authority
➛ identifying Himself as I Am - God
Jesus was not crucified for healing the sick.
Jesus was not crucified for casting out demons.
Jesus was not crucified for raising the dead.
Jesus was crucified because He claimed to be God.
In being the Truth, what Jesus said trumped what was said in the Old Testament when there is conflict.