This chapter has two parts. The first explains what is the effect of the Book of Mormon coming forth:
1. It means the Lord has begun to gather Israel to its land of inheritance.
2. The words of the Lord as revealed to his prophets are being fulfilled.
3. We cannot spurn the doings of the Lord or we will feel the hand of his justice upon us.
The second part is cautionary:
1. Don't spurn the doings of the Lord or deny Christ.
2. Don't deny that revelations can and still come from the Lord.
3. Don't deny that Christ can still perform miracles.
4. Don't abuse the children of Israel!
It's an interesting chapter. We have just read all about Christ's visit among the Nephites, and we're about to get an abbreviated account of the next several hundred years of their history. I'm not sure why Mormon placed it here particularly but I think it serves us as a good reminder that the Book of Mormon is the word of the Lord, its emphasis is on Christ, and we need to both accept it and recognize what its coming forth means. This is the dispensation of the fullness of times and we are a part of it! That is always thrilling to think about. Whether or not we live to see Christ come again, we are a part of a very great work and we can either help it or attempt (and fail) to hinder it. The work will go forward regardless but hopefully we will too, as faithful saints of God.