'Servant' in the Bible

The revelation given by Jesus Christ, which God granted Him, that He might make known to His servants certain events which must shortly come to pass: and He sent His angel and communicated it to His servant John.

And they were singing the song of Moses, God's servant, and the song of the Lamb. Their words were, "Great and wonderful are Thy works, O Lord God, the Ruler of all. Righteous and true are Thy ways, O King of the nations.