Salvation
Philippians 2:12
With fear and trembling work out your salvation.
Context of the passage
Paul, writing from prison, encourages the Philippians toward humility and perseverance, grounding their moral effort in God's own work within them.
Catholic reading
The imperative 'work out' (katergazesthe) shows salvation as an ongoing cooperative process, not a single completed transaction; the Catholic view of salvation as a lifelong journey of grace-enabled cooperation is drawn directly from this text.
Common objection
Paul immediately clarifies in verse 13 that 'it is God who worketh in you,' meaning salvation remains entirely God's monergistic work, with no real human contribution.
Response
Verse 13 affirms that God's grace is the source and enabler of the effort, not that human 'working out' is illusory; Paul commands the Philippians to actively cooperate, precisely because grace empowers rather than replaces genuine human freedom and effort.