Show me a reference versus for that, please.
I believe he’s referencing Phillipians 2:12. Reading that verse in context, however, shows it is referring to the sanctification process rather than the justification. The verse is addressing those who are already members of the body of Christ through faith in Him. The “working out” is a reference to the sanctification process, not being justified before God (which Christ provided for on the cross) and has already occurred. One cannot “work” enough to earn God’s favor.