Power of Prayer

2 Nephi 6:11Wherefore, after they are driven to and fro, for thus saith the angel, many shall be afflicted in the flesh, and shall not be suffered to ^aperish, because of the prayers of the faithful; they shall be scattered, and smitten, and hated; nevertheless, the Lord will be merciful unto them, that ^bwhen they shall come to the ^cknowledge of their Redeemer, they shall be ^dgathered together again to the ^elands of their inheritance.

This line caught my attention as I was reading yesterday. It occurred to me that the United States could have very easily wiped out the Indian population when they were fighting them and relocating them. The explorers to the new world did a lot of damage also. BUT--this scripture shows that not only will they not be fully destroyed but it is because of the prayers of the faithful.
How much power is there in our prayers?
Do we use prayer to bless the life of others?
Enos comes to mind.
I need to ask the Lord to preserve my family.