How does one discover the Truth ?

One must first consider the Whole of Man, only a part of which is Truth. If Man consists of four dimensions, three of which are invisible to the physical dimension [which includes the brain], how can Man think of the Truth which is confined to the Soul or Spiritual Dimension of Man?
Well, one must first find one's Self. Then one's Self has to begin searching for that which one is. This requires use of one's faculty of Intuition.

The Truth did come to us. He is Jesus.

Secondhand truth is not truth, as it cannot be stated, and if it's talked about, it's always misunderstood anyway.

You have to ask yourselves the questions that people do not want to ask themselves. See how, or why they function.

Bare in mind if the topic is controversial ( meaning any topic that does not have any agreement aka "I agree to disagree with you" ) then your asking why doesn't people agree.

Public opinion is the reality, even if the truth is a lie then it will become truth if it is pushed on to people.

This has been understood for a very long time. You make observations. Based on those observations, you make a hypothesis. You then use the hypothesis to predict the result of observations you have not yet made, then go and make them to see if the hypothesis was correct. This is the best way to separate truth from falsehood in every case.