“For it is we who are the circumcision, we who serve God by his Spirit, who boast in Christ Jesus, and who put no confidence in the flesh—” Philippians 3:3 NIV

We do everything for the sake of Christ and not for the sake of the flesh. Things that are of the flesh are temporary and will one day decay, but spiritual things aren’t things that decay since they aren’t physical, so our focus should be on doing right by them primarily. We don’t place our hope in the flesh, yet we still try to do right by it because it can still be used to serve God in its purposes and having it in tiptop shape can help allow us to fulfill Christ’s work better.