Catholic Apologist: I don't think Christ needs to do one more thing for our salvation. We must receive His grace and not reject or lose it.

(In other words, Christ’s work is done, and now there are things we must do - recieve His grace and not reject it or lose it.)

If you're asking if I believe in "once saved, always saved," the answer is no. Christ died for our salvation. That does not mean that ALL will be saved. He did what He had to do. Now we have to receive sanctifying grace, and not lose or reject that precious gift. How do we do that? Following His commands, turning away from sin, confessing and repenting when we do sin, living our faith in him

(Now we are given by this apologist several more things we must do.)

. . .Like Paul said, "work out your own salvation in fear and trembling."

(If we purchase a membership in a health club, we do not purchase it by working out. Our membership is paid for and is not contingent on our working out. If we never work out, we are still members. Christians should be zealous in their working out their salvation. Failing to do so will bring loss to the Christian, but will not cancel our membership [salvation].)