You really don't have to look hard to see the truth; but you DO have to LOOK! Common sense will tell you that if everyone is right- then no one is right because truth is no longer truth. Jesus didn't talk about "a" truth, he spoke of "The" truth.
Consider...
John, Chapter 14 (WEB)
6 Jesus said to him, “I am the way, the truth, and the life. No one comes to the Father, except through me.
There is one and only one way to God- Jesus! If you or I said what Jesus did in verse 6 above, people would think there was something really wrong with us- crazy, sick, a jokester or something equally stupid. Jesus was believed because what he said was true! The way to heaven is in fact the street that Jesus went down- and it ended at the cross; and it IS is a one way street.
BELIEVE THIS BECAUSE ITS TRUE!!!