If there's one moral to Frankenstein that we can agree on, maybe it's this: some things are meant to stay secret. Trying to make nature reveal herself is, well, kind of like peeping through the window of a sorority house: you might get some cheap thrills, but you're also setting yourself up for some serious trouble. On the other hand… if Victor had just told someone about the monster, maybe none of the tragedy (or a lot less of the tragedy) would have happened. So, what's the deal with secrecy? Just like with everything else in this book, we can't make up our minds.
Victor's obsession with secrets causes his downfall.
Victor was right to keep the monster a secret: nobody would have believed him, and he probably would have gotten himself locked up.