Have you tried a modern, expressive, strongly typed functional language like Scala or Haskell? I can well believe that go would be an improvement over Java, but Java's not exactly state of the art these days.
With regards to security issues, I was under the impression that since oracle took it over, Java has had prevalent issues that have just been ignored by Oracle. Quick search seems to agree..
I have played with Haskell and really enjoyed the language. Although imperative languages are my bread and butter it certainly gave me a different approach to programming, primarily stepping away from an OO design and love of recursion!
Haskell is a lovely language and everyone should dabble in it for a while, for that very reason: because it makes you look at programming differently.
Nor was it when it was created. It was born outdated (just like go!).
Writing in Go isn't as strict or structured as Java which I really enjoy. I used to write a lot of C++ and although I was never a pro, I did really used to enjoy programming in it. Go is certainly a breath of fresh air to develop in in comparison and I find that I can write more concisely and if anything performance seems to improve as I am not making trivial mistakes that "powerful" languages like C++ allow me to repeatedly make. KISS.
As always, it's horses for courses.