What a confusion, what a blasphemy to suggest that though Jesus began our work of salvation, we, by our merits, need to complete it. How dare we think that we need to finish what He was unable to finish.
I'm pretty insecure. I have reason to be insecure. There is very little I do that doesn't fall short of what I, and others, hoped to accomplish. On rare occasions my wife accuses me of being a perfectionist. We both laugh heartily at the idea. We've learned to be satisfied with me making a pretty good attempt at things. I do okay.
But, of course, to simply be okay at conforming to God's perfect standard is to fall way short. It falls way short of my own standard.
The Apostle Paul writes, For our sake, He made Him to be sin, so that in Him we might become the righteousness of God.
Me? The righteousness of God? It's hard to imagine. But this is God's reality. That means it's the real reality. For there is therefore no condemnation for those who are in Christ Jesus.
So it's done, finished. There's absolutely nothing left to do, for the Lord Jesus finished everything that needed to be done.