Now the completion of the sign:
When all that has been described has happened, and the remnant will "begin to know these things," that beginning is the sign. Has it happened? Is it happening? Then who is the "remnant" that has or will "begin to know" about the Book of Mormon to fulfill the sign?
We've lost the history of Joseph Smith's efforts to locate the "remnant" of the Nephites. The first mission to locate them was called by revelation in the first 5 months after the church was organized. (D&C 28: 8-9.) Oliver was called and later that same month Peter Whitmer was also called. (D&C 30: 5-6.) This began an effort to locate the "remnant" that continued after the death of Joseph Smith. That will take some time to set out and cannot be dealt with in this post. We'll get to it.
When the remnant is at last identified, and have been given the Book of Mormon, and start to know about their history and the Lord's covenants with them, that will be the moment at which the "sign" given by Christ will have occurred.
It is when this happens that all of us will "know that the work of the Father hath already commenced." Or, in other words, the Father's hand is in motion to finish up what He promised to accomplish. What is it He intends to accomplish? What does it mean "fulfilling of the covenant?" What does the reference to "the people who are of the house of Israel" mean? How broadly will this final work of the Father spread? How many of those who are included in the covenant to Israel will become affected by the Father's work fulfilling the covenant?
Assuming the work "commences" at that time, how long will it take for the work to be completed? Will it be a single generation? (JS-M 1: 34-37.) How long is a "generation?"
Why is the fulfillment to result in "the house of Israel" being given their covenant again?
How can we participate?
Why would the "sign" be given? If it was given to inform us, how can we watch to behold the sign when it happens?
Is there any indication that the sign is now unfolding?
If the organized church does not pay any attention to these things, and does not search for the remnant as Joseph did, will that change these promises? Will the covenant of the Father be forgotten by Him if the Saints themselves forget about it? What effect does our neglect have on the Father's covenants?