A torch is something you see with, something you use as an aid to find your way through darkness for example, and eventually to reach somewhere illuminated. Truth is something that you search for, as not something you search with. Truth is the objective of a search. It is somewhere illuminated and absolutely defined, a place of certainty in the mind.
A torch therefore is not an apt symbol for truth, but it is for knowledge. In my understanding, knowledge is that torch that illuminates paths of the mind, enabling us to see our way through fogs of uncertainty, doubt, and ignorance. A torch that when eventually leads us to truth, when its beam hits truth, truth gleams back bright and clear in any amount of darkness through any intensity of doubt. Once in sight of truth, it is all clear, there is no fog, no suspicion or doubt, just the eternal sunshine of truth to see.
A lie is simply what is not truth. It could be just some shine coming from a torch in the hand of someone hiding in the dark, misguiding, leading your astray, distracting you from seeing the truth. It takes some knowledge even to fabricate a lie, and use it to the desired effect.