Philippians 2:5-11
5 Let this mind be in you, which was also in Christ Jesus:
6 Who, being in the form of God, thought it not robbery to be equal with God:
7 But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:
8 And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.
9 Wherefore God also hath highly exalted him, and given him a name which is above every name:
10 That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth;
11 And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.
Jesus was "in the form of God" and "thought it not robbery to be equal with God". Every knee bows to Jesus, and confesses that He is Lord, which is a reference to Isaiah 45:22-23, in which Yahweh says every knee will bow to Him.
Here, Jesus is actually distinguished from God, and in context, it is God who "has highly exalted him, and given him a name which is above every name" (verse 9). Of course, stating that Jesus was in the "form" of God and considered "equality" with God would be superfluous if Jesus were in fact God Himself - there would be no need to mention "form" or "equality"; the author would simply need to say something like, "Jesus, who is God", etc.
In the view of Unitarians who believe that Jesus pre-existed His birth in Bethlehem, this describes the exalted state of Jesus prior to His Incarnation, but others see this as being in reference to His earthly ministry, and having all of the prerogatives of the Lord's Messiah, yet setting them aside to take our sins upon Himself in His death (verse 8).
Finally, the application of an Old Testament passage about Yahweh to Jesus is always valid when the New Testament authors do so, and here, Isaiah 45:22-23 is given an application to Jesus. Yet, notice in the passage that every tongue confesses that Jesus Christ is Lord, "to the glory of God the Father" (verse 11). In each case, Old Testament passages about Yahweh finding their fulfillment in Jesus Christ, who is the express image of Yahweh (John 1:18, 12:45, 14:9-11: 2 Corinthians 4:4, Colossians 1:13-15, Hebrews 1:1-3), are ultimately to the purpose of glorifying God, as God is the one who exalted Jesus to the honor that He is receiving in each instance.