"The word theophany refers to 'an appearance of God to man'. Throughout the OT God manifested himself to man in three forms - human (Josh 5:13), angelic (Judg 13) & non-human form (Gen 15:17).
Many evangelical scholars believe that the angel of the Lord is a pre-incarnation appearance of the second person of the trinity. This is true as well of other theophanies in human form. Occasionally these theophanies and more specifically referred to as 'christophanies'. Neither the OT nor the NT directly identifies Jesus Christ with the angel of the Lord however scholars reason backwards from John 1:18 that no-one has ever seen God the Father."