Not exactly. Based on the word of a being that you area absolutely sure is God.
But that’s part of the question, inevitably. Any being that is even slightly more powerful than mankind could convince you that you KNOW it’s god speaking to you. Your beliefs and feelings would be silly putty for its arrangement.
Further, the sort of “God” this God is can never be fully known to you in practice. Whether or not this is the kind of God you’d want to worship and obey, then, is never fully known to you either.