One of the literary structures we see throughout the Book of Mormon is an argument that is set up as a thesis, followed by the concluding instruction. In the early part of the Book of Mormon, the conclusion is typically introduced with “wherefore.” Thus, these two verses beginning with “wherefore” serve as the conclusion to the thesis that Jacob established in the preceding verses. That thesis was the power of Jehovah. The conclusion is that the powerful Jehovah who rules over nature has, in wisdom, justice, and great mercy, also taken care of humankind.
The first “wherefore” conclusion is that we “seek not to counsel the Lord, but to take counsel from his hand.” This is a nice turn of the phrase, but the concept of counseling the Lord is a commentary on the way humankind would prefer to deal with God. We would much prefer it if God would only act, and counsel, according to our mortal preferences. He does not, and we need to understand that his vision and understanding are greater than ours.
The second “wherefore” speaks of how we put ourselves in a position to receive that divine counsel. That occurs through the atoning mission of the Messiah. While that is the understanding that Nephi taught, and Jacob now teaches, it doesn’t have a specific process included for how that might be done. One of those methods was baptism, as Nephi taught in 2 Nephi 31:4. The other is continuing to live the law of Moses.