'Demonstrate' in the Bible

"I'm headed down the road that everyone who lives on earth travels, so be strong and demonstrate that you're a grown man

May you demonstrate wholehearted devotion to the Lord our God by following his rules and obeying his commandments, as you are presently doing."

Then you will invoke the name of your god, and I will invoke the name of the Lord. The god who responds with fire will demonstrate that he is the true God." All the people responded, "This will be a fair test."