I Thessalonians 5:21 says “Prove all things; hold fast that which is good.” The word prove means to demonstrate the truth or existence of (something) by evidence or argument. However, for me, the most impressive of all the definitions of the word is “to turn out to be.”
"To be" in the infinity of the words is, am, and are. If you use any word from the infinity "to be" it means that the thing being spoken of is absolute in its existence. When you use "to be" there is no doubt or speculation attached to it. "To be" is the one word in the English language that you can completely count on. If you say, "I am a girl." This statement means to convey that there is absolutely no doubt or proof that this statement is not true.
I want to take this English lesson into the spiritual realm for a moment. Remember when Moses asked God what his name was? God answered, “I am that I am.” God used the word "am" because there is no doubt or speculation involved with God. He IS God. He is the definition of existence. Romans 11:36 says, ""For everything comes from him and exists by his power and is intended for his glory. All glory to him forever! Amen." (NLT) Whether we understand it or not, God IS God.
In John 14:6, Jesus said, "I AM the way, the truth, and the life." God IS the truth. So if we want to prove all things as the verse in Thessalonians tells us to, we must find the truth. In essence, we must find God.
Right now, if you are searching for an answer to a problem, you must prove that the answer is right before you take action. How can we prove that something is right? In this case, if we get our answer from God, then we can be sure that our answer will prove to be the truth.
Source: https://www.thevirtuouswomanproject.com/blog/prove-it