Calvinism is the scourge of Christianity.
“In Him is no darkness at all.”
Calvinism , in error at it’s very foundation, is a false doctrine that will burn in hell.
So how does quoting 1John 1:5 prove that Calvinism is a false doctrine? In Christ there is no darkness. It doesn’t say in man there is no darkness.
Simply test the ideas out by reading Scripture for yourself. Does the Bible say we're only "partially" sinful or "totally" sinful? Does Scripture teach that GOD is fully sovereign? Or do we determine our own destinies?
Regardless, it's not Calvinism that saves a person's soul. The doctrines of election and Divine Sovereignty are far secondary to that of faith and repentance. They're important, but not essential.