In Christ, we keep improving. This is a mystery that defies the law of nature. In this fallen world, everything eventually breaks down.
If someone's art is inspired by demons...as most art is these days...their work may start out good, as in skillful and able to capture people's interest (though not good in essence). Then, over time, their work depreciates...tends to become darker, more twisted...and eventually, the talent they once had is no longer apparent. This pattern happens time and again with authors, musicians, and artists.
For example, J.K. Rowling, Beyonce, Snoop Dogg, and Stevie Nicks all depreciated over time. There always was a seed of darkness in their works, which grew and blossomed into bad trees producing corrupt fruit. Their early work is great, but their later work is awful, after the demonic muses left them.
For Christians, though, the opposite occurs; they continuously improve, becoming wiser and more skillful.