God made the fly but forgot to tell us why.

Savyasachi: There is a saying that I have heard many times: "God made the fly but forgot to tell us why." Why did God make the fly?

Sri Chinmoy: God created flies and insects to make Himself perfect. Otherwise, you will say that God is only good. No, God needs all qualities in His creation, both good and bad. Flies cause irritation. This irritation is not a good quality, true. But God had to create that quality too, to prove that He is both night and day, good and bad. God said, "I am in the fly, and I want to develop irritation-power so I can say I know I have that capacity. Then only can I be completely perfect."

Original source: Sri Chinmoy Library

Sri Chinmoy also answered this question in another way:

Omar: Why did God create flies?

Sri Chinmoy: God created flies so that the mind will not feel miserable. God tells the mind, "I have created something to compare with you. You can't stay in one place. You fly from one object to another. So I have created a friend for you. It is the fly, which is also restless, Oh mind, since you are not able to remain calm and quiet, then I will show you that you have a friend on earth: the fly. Then you will be able to enjoy its company, if not outwardly then inwardly." So God is very kind to the mind. He tells the mind to look around and appreciate the fly, for the two of them can become good friends. Again, there comes a time when the fly becomes tired and exhausted, and stops flying. At that time God again speaks to the mind about the fly: "If flies can remain calm and quiet, how is it possible that you can't do the same thing? Don't accept defeat. If the fly can do something in a positive way, then you should try to do the same thing and defeat it. So be calm and quiet and don't accept defeat."

• From: Smile of the Beyond at Sri Chinmoy Library