Helaman had proven through his faithfulness and diligence that he stood blameless before God,
'Therefore, O ye that embark in the service of God, see that ye serve him with all your heart, might, mind and strength, that ye may stand blameless before God at the last day' (D&C 4:2). Nephi had done just that, and because of his diligence, he was about to receive a great blessing from the Lord according to the promise,
'All victory and glory is brought to pass unto you through your diligence, faithfulness, and prayers' (D&C 103:36).
Unfortunately, most of us have a difficult time with diligence. To us the Lord has said, 'be not weary in well-doing, for ye are laying the foundation of a great work...The Lord requireth the heart and a willing mind; and the willing and obedient shall eat the good of the land of Zion in these last days' (D&C 64:33-34). And so, it is our charge to be as Nephi, not weary in well-doing, but diligent - serving him with all our heart, might, mind and strength.
Blessed art thou, Nephi, for those things which thou hast done; for I have beheld how thou hast with unwearyingness declared the word, which I have given unto thee, unto this people. And thou hast not feared them, and hast not sought thine own life, but hast sought my will, and to keep my commandments (Helaman 10:4)
Joseph Smith taught that one of our goals should be to prove to the Lord that we are willing to serve him at all hazards. This means that we are willing to lay down our life for the cause. It means that we are willing to submit our will to the Lord's. It means that we are willing to follow the counsel, 'For whosoever will save his life shall lose it: and whosoever will lose his life for my sake shall find it' (Matthew 16:25). Nephi is a great example of this principle. He was willing to preach to hardened Nephites. At the peril of his own life, he openly declared the wickedness of secret combinations in the very presence of these secret murderers. He undoubtedly had proven himself in a myriad of different ways in a myriad of circumstances which are not recorded in our abridged record. He had served the Lord "at all hazards."
And now, because thou hast done this with such unwearyingness, behold, I will bless thee forever; and I will make thee mighty in word and in deed, in faith and in works; yea, even that all things shall be done unto thee according to thy word, for thou shalt not ask that which is contrary to my will.
Behold, thou art Nephi, and I am God. Behold, I declare it unto thee in the presence of mine angels, that ye shall have power over this people, and shall smite the earth with famine, and with pestilence, and destruction, according to the wickedness of this people. (Helaman 10:5-6)
Nowhere else in the scriptures is there an instance in which the Lord so completely places his implicit trust in one of his prophets. In effect, Nephi is given a "blank check" from the Lord. He is given the privilege of using the powers of the Lord however he seems fit because the Lord knows that he was not capable of 'unrighteous dominion' (D&C 121:39). This "blank check" is granted because Nephi had become one with God. This is what the Lord had prayed for in his intercessory prayer, 'That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us' (Johnn 17:21). Well, Nephi had accomplished this remarkable task. The result was the great blessing of God's power, the blessing of the sealing power, and the reassurance that his life was in accordance with the will of God.
Behold, I give unto you power, that whatsoever ye shall seal on earth shall be sealed in heaven; and whatsoever ye shall loose on earth shall be loosed in heaven; and thus shall ye have power among this people (Helaman 10:7).
