In Job, chapter 1, God summons Satan before Him, and asks him:
"Have you considered my servant Job? There is no one on earth like him; he is blameless and upright, a man who fears God and shuns evil."
In response, Satan says, in effect,
"The only reason he serves You is because You give him good things. Take away the things, and he'll curse You to Your face!"
God lets Satan take away all the "things" that Job has, and at the end of chapter 1, Job's response is:
"The LORD gave and the LORD has taken away; may the name of the LORD be praised."
Then, in chapter 2, God again summons Satan to stand before Him. He proceeds to say exactly the same thing about Job, except that He adds a statement about integrity. God says to Satan this time:
"Have you considered my servant Job? There is no one on earth like him; he is blameless and upright, a man who fears God and shuns evil. And he still maintains his integrity, though you incited me against him to ruin him without any reason."
Why did God add the comment about integrity in chapter 2, and not include it in chapter 1? The reason is that in chapter 1, Satan might have been right! The only way you can know if someone really has integrity is after they have been tested. Otherwise, it may be just talk!
Proverbs 20:6 captures the essence of that concept quite well.
"Many a man claims to have unfailing love, but a faithful man who can find?"