The syntax is very complex here in Jacob 6:9–10, but basically Jacob is rhetorically asking his listeners to acknowledge that if they are evil they will stand guilty before the bar of God and, according to God’s justice, they will be sent into eternal punishment. In the original text, each of the two stages in God’s judgment is preceded by the subordinate conjunction that (identified above as 1 and 2). These two that ’s are instances of what may be called the repeated that since they each repeat an earlier that (identified above as 0). In other words, there is a that both before and after an initial conditional clause, thus “know ye not that if S0 that S1 and … that S2” (where S0, S 1, and S2 are finite clauses). The repeated that is considered ungrammatical in standard written English, but it is common in spoken English. Some instances of the repeated that have been edited out of the text, as in the following two examples:
In the first example, the initial that was deleted; in the second example, the repeated that was deleted. But other passages have not been edited, as in the following two examples:
There are many more examples of the repeated that, with some edited and some left unedited in the text. For further discussion, see under THAT in volume 3.
Here in Jacob 6:9–10, Joseph Smith removed the second repeated that in his editing for the 1837 edition. But the first repeated that was not removed. It would appear that the reason for removing the second that was because the original syntax was extremely awkward, given the preceding adverbial phrase and parenthetical clause (“according to the power of justice / for justice cannot be denied”).
Another factor that has complicated the syntax for this passage has been the punctuation. The continual use of question marks in the 1830 edition at least preserved the connection between the two stages of God’s judgment and maintained both stages as part of Jacob’s rhetorical question. But otherwise the accidentals made the passage almost incoherent:
The punctuation for the second edition (1837) considerably improved the reading; but by deleting the that, Joseph Smith separated the second stage from the first stage of God’s judgment, with the result that the second stage no longer belongs to Jacob’s rhetorical question:
The critical text will restore the second repeated that and parse the passage so that both stages of God’s judgment are contained within Jacob’s rhetorical question:
Summary: Restore in Jacob 6:10 the second repeated that (which Joseph Smith deleted in his editing for the 1837 edition); the two repeated that’s help the reader identify Jacob’s rhetorical question as referring to two different stages in God’s judgment of evildoers.