It is, of course, true that no one can earn the salvation on his own power, but does so with Christ "working in him".
These threads have shown me just how far the Roman Catholic church is from the Scriptural understanding of Christ's atonement.
His righteousness is what saves us; not our own. His obedience is what earns God's mercy; not our own. His suffering the punishment due our sins is what acquits us; not our own. His blood cleanses us, not our own.
And He does this perfectly and irrevocably because it is by the will of God.