Philippians 3: what are you proud about?

Paul used to be proud about his lineage, education, and specially, his devotion in following the Torah.
The citizens of Philippi had advantages such as being considered Romans to the point of not paying taxes. A good Roman would declare that "Caesar is Lord!"
A Christian is proud of not what he does, but of what he received: justification by faith, made holy by faith.
A Christian is citizen of Heaven, and a Christian declares that "Jesus is Lord!".
A Christian is one who is the process of being transformed to the image do Jesus, to the point of resurrect from the dead:

10-11 I gave up all that inferior stuff so I could know Christ personally, experience his resurrection power, be a partner in his suffering, and go all the way with him to death itself. If there was any way to get in on the resurrection from the dead, I wanted to do it.