'Messenger' in the Bible

Paul, an apostle (not commissioned and sent from men nor through the agency of man, but through Jesus Christ—the Messiah—and God the Father, who raised Him from the dead),

but even if we or a messenger out of heaven may proclaim good news to you different from what we did proclaim to you -- anathema let him be!

and my trial that is in my flesh ye did not despise nor reject, but as a messenger of God ye did receive me -- as Christ Jesus;