Mormons perform saving ordinances for the dead based on the idea that our works can bring salvation for someone else; they can be judged as worthy because we did something on their behalf.
(Sounds familiar….almost like something in the Bible….)
One reason I was taught that the Book of Mormon is superior to the Bible is because it teaches that Christ’s atonement wasn’t just for sin, but was for weaknesses too, or to succor us.
I was always taught that in the LDS church, we had a higher, more privileged understanding of Jesus and His atonement.
But now I’m realizing — quite strikingly so — that LDS people actually don’t understand the atonement better than the rest of Christendom. They are missing a critical concept — the worthiness of Jesus standing in place of our worthiness.
They don’t know that his blood covers us! And in being covered, we don’t need to prove our own worthiness — because his worthiness covers us!

It was such an eye opening thing for me to see the atonement differently lately.
I don’t think Mormons get this. That his righteousness covers us. That we are worthy only because he is worthy, and he gave us his worthiness.
So you know how Mormons do work for the dead? This idea that my work can count for someone else’s salvation, or someone else’s righteousness?
It’s a true principle but they twisted it.
The truth is that Jesus’s work counts for my salvation and my righteousness. It’s salvation by proxy!
But a human can’t give that to another human. Only God can give it to humans.
Mormons still think they need to earn or work toward their own worthiness.
Why do we have worthiness interviews? Why do we need to prove ourselves? What are we measuring up to?
The only question should be “do you accept Jesus’s worthiness on your behalf?” and then it’s done.
Just like temple work is a check mark. It’s done. The deceased person doesn’t need to earn the temple work we did. It’s complete.
Likewise, Jesus’s sacrifice is complete.