In one interpretative model the man Jesus only became Messiah after his baptism or after his ascension. The model I prefer is that the eternal Son of God was already called Messiah (Anointed One, King, Lord, Shepherd) in the Old Testament. When he was conceived by the Holy Spirit (as in Luke 1:35) he was named Jesus by his parents (as in Matthew 1:21). That means he was already Messiah before coming into our world (as in Luke 2:11, 26).
The letter is addressed to -pasin tois agiois en christo Iysou- to all the ones who are set apart in Messiah Jesus (1:1). And Paul prays for them to have peace from God our Father and from -kuriou Iysou Christou- our Lord Messiah named Jesus (1:2). The same expression comes at the beginning of each of Paul's letters to the churches, and it also suggests that the second Person of the Trinity was known as Lord Messiah in the Old Testament and became known as Jesus in his incarnation.
(a) The eternal Son of God, who was known as Lord Messiah in the Old Testament, pretended for a thirty year period to be the man Jesus. His - kenosis- self-emptying would be like an actor wearing a mask or playing a role. This model would deny the comparison -touto phroneite en umin o kai en Christo Iysou- let the mind of Messiah Jesus be in you (Philippians 2:5). How could we put on such a mask of pretense?
(b) The -kenosis- self-emptying of the eternal Son of God, who was known as Lord Messiah in the Old Testament, involved taking birth among us. He therefore experienced human life but without the usual temptations common to all humans. This is on the assumption that feeling the strong pull of sexual temptation for example is not compatible with his eternal perfection as Son of God. Obviously this model would clash with the model of a high priest who had to be tempted in exactly the same way as we are (Hebrews 4:15).
(c) In his -kenosis- self-emptying the eternal Son of God took human flesh (incarnation means going into human flesh) and was tempted just as we are. The difference is that our moral character is flawed by original sin. He became like us in every way except that original sin. He then remained perfect and without sin because he was able to reject every temptation by his moral character and strength of will. We in turn, having been forgiven and filled with loving gratitude, must reject every temptation by firm resolve and every victory will strengthen us in sanctification. That model would require him and us to live by the legalism and self-effort, which Paul rejected so vehemently in Galatians 3:1-3.
(d) A fourth model is based on Paul's repeated use of the word -sarx- human flesh in Romans 7:18-8:9. Using the language of modern psychology we defined -sarx- flesh as the natural instincts we received through the genes of our parents as they were twisted by our early childhood experiences and the later traumas of our life. And Paul's point was that our unaided flesh has no desire to do what is required of us such as going the extra mile, turning the other cheek, loving enemies, or praying according to the mind of God. That means no amount of self-effort or will power can force our flesh into -dikaiosune- righteousness (Romans 7:15-24). Moral perfection is only possible by looking away from our flesh and its good and bad desires, and looking to the Spirit to inspire and perfect us (Romans 8:4-7). In this model the Son of God emptied himself of everything except his eternal loving relationship to the Holy Spirit. And every victory over temptation, and every expression of creative love, was by looking away from his flesh and looking to the power of the Spirit. That same power is also available to us as we look to Him in faith.
That this is in mind is confirmed by the exhortation -tyn eauton sotyrian katergazesthe- work out your own salvation- (2:12) -theos gar estin o energon en umin kai to thelein kai to energein uper tys eudokian- for it is God (the Holy Spirit) who energizes both you will and your creative energy to achieve what pleases Him (2:13).
This fourth model of -kenosis- has the great advantage of explaining and interconnecting Paul's teaching in other epistles with a larger Trinitarian model. It then enables us to translate -os en morphy theou uparchon- who continuing to exist in his divine form (essential nature) -ouch arpagmon ygysato to einai isa theo- did not consider the privileges of divinity a prize to be held on to (2:6), -alla eauton ekenosen morphyn doulou labon- rather he emptied himself of those royal privileges to take the absence of privilege of a servant -en omoiomati anthropon genomenos- by the act of becoming became fully human (2:7).
At first sight that law court substitutionary model fits Paul's longing -ina Christon kerdyso- that I may gain the Messiah (3:8). We then translate -kai euretho en auto, my echon emyn dikaiosune tyn ek nomou- and be found in Him, not having my own justification based on legal performance (3:9), -alla tyn dia pisteos Christou, tyn ek thou dikaiosunyn epi ty pistei- but the kind of justification that comes through faith in the Messiah, which is a justification from God based on faith alone (3:9).
Greek speaking theologians understand the noun - diakaiosune- as a righteousness of moral character which is effected in us by the Holy Spirit. We saw how that was clearly what Paul had in mind in 2:12,13. And this section also begins with a contrast between -tyn katatomy- the flesh cutting, a derogatory reference to circumcision, and the true circumcision of the heart (as in Romans 2:28- 29) -oi pneumati theou latreuontes kai kauchomenoi en Christo Iysou kai ouk en sarki pepoiothotes- who are those who serve God in the Spirit, and rejoice in Messiah-Jesus rather than trusting in their own fleshly performance (3:2,3).
Paul then points out that he had tried taking the route of fleshly self effort (3:4-6, as in Romans 7:14-24). He claims that he had been -kata dikaiosune tyn en nomou amemptos- blameless by the standards of Jewish law (3:6), but now considered that so much refuse (3:7-8).
The reason is -ina Christon kerdyso- that I may gain the approval
of the Messiah (3:8) -kai euretho en auto, my echon emyn dikaiosune
tyn ek nomou- and be found in Him, not having my own righteousness
based on self effort (3:9), -alla tyn dia pisteos Christou, tyn
ek thou dikaiosunyn epi ty pistei- but the kind of righteousness that
comes through faith in the Messiah, which is the righteousness created
in us by the Holy Spirit of God as we look to him in faith.(3:9
a paraphrase which picks up the thread of the argument from 3:2,
and previously in 2:12,13).