7 But whatever things were gain to me, those things I have counted as loss for the sake of Christ. 8 More than that, I count all things to be loss [c]in view of the surpassing value of [d]knowing Christ Jesus my Lord, [e]for whom I have suffered the loss of all things, and count them but rubbish so that I may gain Christ, 9 and may be found in Him, not having a righteousness of my own derived from the Law, but that which is through faith in Christ, the righteousness which comes from God on the basis of faith… Philippians 3:7-9 NASB
The Greek word for faith can also mean faithfulness. So the 2011 NIV has a footnote pointing out that the verse could be saying through the faithfulness of Christ rather than through faith in Christ.
If it means through the faithfulness of Christ, then Paul is not repeating himself at the end when he emphasizes that this kind of righteousness comes by faith.
Also, if it means through the faithfulness of Christ, then Paul is making the contrast sharper between righteousness based Paul’s own efforts and righteousness based on Christ’s faithfulness.
Either way, the contrast is there. If we are not found in Jesus, having a righteousness that he provides when we put our trust in him; then we are stuck with whatever righteousness we can manage to achieve. And that’s not enough.
– SSXG