Truth, is the way it is perceived by whoever holds that truth, in that you could say there is no real truth but only ones perception of how it is perceived.
An untruth which is known to be a lie is not a perception of the truth but an injustice towards another.
If an untruth is told and then retracted it becomes a confession.
In many situations there is often a way of telling the truth without being entirely honest, by simply applying the use of semantics, a play on words.
The only real truth is the word of God.