Display monitors and laptop screens are certainly very necessary when we are doing work on the computer.
These monitors and screens tell us whether the computer is doing what we want it to do.
In other words, through the monitor or screen, we are "communicating" with the computer.
Human beings don't have a monitor or screen to tell others what they are thinking and what their intentions are.
So others won't really know what is going on within us.
But we all have a heart, and only we ourselves know our true motives and intentions and what is going on in our hearts.
But we are not the only one who have access to our hearts.
The 1st reading tells us that the Lord God searches the heart and probe the loins, and He gives each man what his conduct and actions deserve.
We have to admit that not all our motives and intentions are pure and good, and may even be devious and perverse.
Let us surrender our hearts to the Lord through prayer, penance and alms giving, so that He can cleanse and purify our hearts and that we will do what is good and true and loving before His eyes