Being (υπαρχων). Rather, "existing," present active participle of υπαρχω. In the form of God (εν μορφη θεου). Μορφη means the essential attributes as shown in the form. In his preincarnate state Christ possessed the attributes of God and so appeared to those in heaven who saw him. Here is a clear statement by Paul of the deity of Christ.

A prize (αρπαγμον). Predicate accusative with ηγησατο. Originally words in -μος signified the act, not the result (-μα). The few examples of αρπαγμος (Plutarch, etc.) allow it to be understood as equivalent to αρπαγμα, like βαπτισμος and βαπτισμα. That is to say Paul means a prize to be held on to rather than something to be won ("robbery").

To be on an equality with God (το εινα ισα θεο). Accusative articular infinitive object of ηγησατο, "the being equal with God" (associative instrumental case θεω after ισα). Ισα is adverbial use of neuter plural with εινα as in Revelation 21:16.

Emptied himself (εαυτον εκενωσε). First aorist active indicative of κενοω, old verb from κενος, empty. Of what did Christ empty himself? Not of his divine nature. That was impossible. He continued to be the Son of God. There has arisen a great controversy on this word, a Κενοσις doctrine. Undoubtedly Christ gave up his environment of glory. He took upon himself limitations of place (space) and of knowledge and of power, though still on earth retaining more of these than any mere man. It is here that men should show restraint and modesty, though it is hard to believe that Jesus limited himself by error of knowledge and certainly not by error of conduct. He was without sin, though tempted as we are. "He stripped himself of the insignia of majesty" (Lightfoot).