Glass: Easy access, made by man, fabricated, can be made to look like other things but can never be a diamond, even if it is shaped like one.
Diamond: have to search for them, dig them out, cannot be made by man, a strong mineral deposit of coal. Takes time to form, and is worth more than many sheets of glass.
We will say that glass is the people who are in the world, many of them can be used for different purposes. Windows, mirrors, cups, desktops, windshields, etc.
People can be found everywhere in the churches fitting wherever they can. Some have been made from windows into stained glass, beautiful-looking, decorative mirrors to reflect images of others because they do not want to see themselves.
A glass cup is useful for drinking water, but if it is cracked there is no more use for it. A desktop with a large heavy piece can hold lots of weight but all it takes is a hit and the piece can not hold anything. Though many purposes all the good can be turned to bad. Good deeds into selfish desires. Abilities turned into Pride. Righteousness becomes sin. Let's compare it to diamonds.
Diamonds are small yet stronger than glass. Diamonds have a clarity better than glass after being cut from the rough dark coal. Diamonds are rare and valuable. Diamonds are used to cut glass. Diamonds are unique, though tried to duplicate, you can never get each one to look the same.
Even diamond dust is used. Nothing is thrown away.
We’ll call Diamonds the children of God. Though they were searched out, worked on and developed in time. They have more purpose than when they were originally in the rough. How many would choose to be glass? Though it is useful. Some pieces of glass can be fitted to take the place and anyone even an amateur can be fitted to make fit.
When a piece of glass is lost, you just replace it, but when a diamond is lost you search everywhere for it hoping to find it. You will go to great lengths to ensure you find it.
Do not settle to be like glass when you can be diamonds.