A.T. Robertson Commentary Philippians 2:7

"but emptied himself, taking the form of a servant, being made in the likeness of men;" — Philippians 2:7 (ASV)

The form of a servant (μορφην δουλου). He took the characteristic attributes (μορφην as in verse 6) of a slave. His humanity was as real as his deity.

In the likeness of men (εν ομοιωματ ανθρωπων). It was a likeness, but a real likeness (Kennedy), no mere phantom humanity as the Docetic Gnostics held. Note the difference in tense between υπαρχων (eternal existence in the μορφη of God) and γενομενος (second aorist middle participle of γινομα, becoming, definite entrance in time upon his humanity).