Free Will is the very purpose of The Creation Program. We humans are not the only living things with free will. The spiritual beings, represented and classified in the Hierarchy of Angels, have free will. In fact, one may explore the possibility that they actually are free will that has been programmed into being in a living, spiritual form.
We know that many angels have fallen. They have chosen to stop serving The Loving Programmer, and have chosen to spend eternity in thrall to Hateful Error Pain Death. Similarly, we see family, friends, and neighbors falling away from truth and moving into the awful realm of Hateful Error Pain Death. We pray endlessly that they will recover and return, but know that many will not.
On a vastly lower level, many of us have been around dogs and horses. We see that they, too, have a certain amount of free will that’s commensurate with their mental ability. When a dog decides to chew something it shouldn’t, there’s sometimes a degree of willful disobedience at work. “I’ll show them!”, it may be saying to itself in anger at being left alone, purposefully shredding the brand new couch on which the most uppity members of what it sees as its pack are allowed to sit while keeping him off it. Similarly, if a horse ignores the clear instructions of its rider and intentionally runs under low-hanging branches, it is sometimes clearly seen to have done so from an intentional malevolence.
The Loving Programmer programmed dogs and horses into existence so that we humans would have beings that we could love and could program to follow our instructions. He did that so we could get at least a hint of His distress when a creature we love intentionally does something hurtful. On the other side of that same coin, the joy we feel at a beloved pet’s obedience lets us know some of His joy when we free-will creatures cheerfully obey His Operating Instructions.