Romans 11

Paul teaches the Romans, both Jew and Gentile, that grace and works go hand in hand making it clear -

"...that it is by grace that we are saved, after all we can do." (Book of Mormon | 2 Nephi 25:23)

Why else would he speak of both the righteous and wickedness (or cutting off) of Israel or in other words speaking of some righteous Israelites -

"Even so then at this present time also there is a remnant according to the election of grace." (New Testament | Romans 11:5)

I was impressed with the words of Isaiah -

"According as it is written, God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear;) unto this day." (New Testament | Romans 11:8)

The meaning of God given "spirit of slumber" is the God given eternal gift of agency where man may choose to slumber, not see, or not hear. It becomes clear that these, even though they might claim to believe will be cut off. That is why Paul shares the relationship of grace and works -

"And if by grace [or grace only], then is it no more of works: otherwise grace is no more grace. But if it be of works [or works only], then is it no more grace: otherwise work is no more work." (New Testament | Romans 11:6)

I have placed some imput in brackets which I believe makes the verse very clear.

"O the depth of the riches both of the wisdom and knowledge of God! how unsearchable are his judgments, and his ways past finding out!" (New Testament | Romans 11:33)