[Mr Rogers]

No, it is not nonsense.

For by grace you have been saved through faith. And this [grace] is not your own doing; it is the gift of God, 9 not a result of works, so that no one may boast.

“Ephesians 2:8

For by grace (thi gar xariti).
Explanatory reason. “By the grace” already mentioned in verse 5 and so with the article.

Through faith (dia pistewv).
This phrase he adds in repeating what he said in verse 5 to make it plainer. “Grace” is God’s part, “faith” ours.

And that (kai touto).
Neuter, not feminine tauth, and so refers not to pistiv (feminine) or to xariv (feminine also), but to the act of being saved by grace conditioned on faith on our part. Paul shows that salvation does not have its source (ex umwn, out of you) in men, but from God. Besides, it is God’s gift (dwron) and not the result of our work. “

http://www.studylight.org/com/rwp/view.cgi?book=eph&chapter=002&verse=008

[1000 silverlings]

again, the law of faith excludes boasting. If you could believe all on your own you could boast about it. God says you can’t.

[1000 silverlings]

And another point, why would any man think he himself is the source of grace? Or boast about it? Grace is an attribute of God. You cannot separate out the grace and the faith-- one is saved by grace through faith-- it is one thing, and that is why the word "that" refers to both and the "it" refers to "that"