The truth means the whole, all that is, the total. All that is -- how can you define it? It is unbounded, infinite. Definition means drawing a line around it, locating it, saying, "This is it." But there is no way to define truth, because there is no way to draw a line around it. It is infinite, it is eternal, it has no beginning, no end.
People who have tried to define truth say, "Truth is that which is." But that is tautology.
The question remains the same, the mystery remains unsolved. "Truth is that which is" -- what have you added? Have you made it a little simpler than before? You can call it "that which is" or you can call it truth, or you can call it God, but you are simply using names, words, labels, for something which is basically indefinable.
Truth cannot be defined, although it can certainly be experienced. But experience is not a definition. A definition is made by the mind, experience comes through participating. If somebody asks, "What is a dance?" how can you define it? But you can dance and you can know the inner feel of it.
God is the ultimate dance. You will have to learn ecstatic dancing to experience God.
God is the dance where the dancer disappears. Then the experience arrives, showers on you, and you KNOW. But that knowing is not knowledge, that knowing is wisdom.