I read a sign recently. It said, "Truth is truth even if no one believes it. A lie is a lie even if everyone believes it."
Too often today Christians shrink from telling a biblical truth because we're afraid of what people might say, or what they might call us. So, we don't say anything. I've linked this blurb to a video clip that illustrates why we should share the truth--the only real truth. Please listen to it.
Too often Christians give up sharing the gospel because people have finally come up with the definitive rebuff. Here's an example:
Joe Christian: "Jesus said there is only one way to heaven."
Sally Sinner: "Well, I don't agree with that."
Society simply disagrees with the Bible, or discounts the Christian as an intolerant fool who believes all that stuff. To make such a statement as Sally Sinner in the aforementioned dialog, one assumes their opinion is as valid as God's! Think about that a minute. The supreme arrogance of the human species to think that whether or not they agree with Scripture will change its truth is a revolting irony. But there you have it.
Still, Christians are required to share their faith; whether or not people believe does not expiate our obligation. Watch the link. http://youtu.be/ZhG-tkQ_Q2w
It'll change your perspective.