If we say that we have not sinned, we make God a liar, and his message isn’t in our hearts.
1 John 1:10
If you believe the truth, then you reject the lie. Conversely, if you believe a lie, then you reject the truth. Truth and lies are polar opposites and nothing or no one can cause them to live together in peace!
If you judge a claim on it's own merits it is easy to determine whether it is a truth or a lie. "It is hot outside" can be confirmed or denied by stepping outside and seeing how it feels. It is simple enough for even a child. Let reality be the judge. The problem comes when you accept a statement based solely on its source, not the evidence of it's veracity. You come to trust the wisdom of PhD's, doctors, counselors, peers, teachers, and thousands of other sources of "truth." You believe what you hear because of the person who said it, never testing their assertion against reality.
But aren't we supposed to trust God's Word because of who He is? Of course we should, but there is a huge difference. God is not offended when we test His Word to see if it is really true. I can believe what God says because He is God, but also because I have never seen even one example of something God said not being true.
Here is the bottom line. The Christian life should consist of a daily testing of the Word of God. Every moment provides an opportunity for the follower of Jesus to see if what God says is true. Every day the Word of God is applied to situation after situation. Confidence in God's Word builds because it works and always works.
The success rate of God's Word is 100%!