I really like Calvin and Hobbes cartoons. They're hilarious.
Every once in a while, they also illustrate philosophical points really well. This is one of them.
This cartoon illustrates a point we all intuitively know — we have free will. Life wouldn't really make sense if we didn't.
Although, there have been some really smart people who have written otherwise. (One of them being Stephen Hawking, in his book The Grand Design.)
Materialism, or naturalism, says that there is no spiritual dimension to this world. All that exists is the physical. Only what you can see, touch, taste, hear, or smell.
If this is true, then we have no free will. Free will requires there to be something other than the physical.
If we are only physical beings then our mind is only physical. And if our mind is only physical, then our thoughts are only physical. We are not actually thinking what we want to think. Our thoughts are just the materials in our brains doing whatever the natural processes are causing them to do.
So, then, our decisions are happening just because of our "genetic material," not because we actually chose something.
And we all intuitively know that doesn't work.
In reality, like this cartoon illustrates, life only makes sense if free will exists. And the Christian worldview makes great sense of that.