When the mind realizes the limitation, the narrowness, the finiteness of thought, then only it can ask the question: what is truth? Is this clear? I do not accept truth given by philosophers - that's their game. Philosophy means love of truth, not love of thought. So there is no authority - Plato, Socrates, Buddha, but Christianity has not gone into that very deeply. They have played with words and symbols, made a parody of suffering and all the rest of it. So the mind rejects all that.