Commentators are unanimous that this verse explicitly identifies the church's ultimate spiritual enemy. The 'great dragon' is given four distinct titles: the 'old serpent' (linking him to the tempter in Genesis), the 'Devil' (a Greek word for 'accuser' or 'slanderer'), 'Satan' (a Hebrew word for 'adversary'), and the 'deceiver of the whole world.' This clarifies that these are not different beings but various descriptions of the one great foe of God and humanity.