I glory in plainness; I glory in truth; I glory in my Jesus, for he hath redeemed my soul from hell. (Book of Mormon, 2 Nephi, 2 Nephi 33:6)
"Even so faith, if it hath not works, is dead, being alone. Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works. Thou believest that there is one God; thou doest well: the devils also believe, and tremble." (New Testament, James, James 2:17-19)
We demonstrate our faith by our good works.
"For we labor diligently to write, to persuade our children, and also our brethren, to believe in Christ, and to be reconciled to God; for we know that it is by grace that we are saved, after all we can do. And, notwithstanding we believe in Christ, we keep the law of Moses, and look forward with steadfastness unto Christ, until the law shall be fulfilled. For, for this end was the law given; wherefore the law hath become dead unto us, and we are made alive in Christ because of our faith; yet we keep the law because of the commandments." (Book of Mormon, 2*Nephi, 2 Nephi 25:23-25)
Salvation is by the grace of Christ after all we can do. The Law of Moses is dead but we are still going to observe it because God gave us the Law and we will observe it until Christ tells us something else to do.
"Or do ye suppose that the Lord will still deliver us, while we sit upon our thrones and do not make use of the means which the Lord has provided for us?" (Book of Mormon, Alma, Alma 60:21)
Captain Moroni answers the question of what is "all we can do"?
"All we do" is not saying that we save ourselves even part-way. What Captain Moroni says is that God has provided gifts of His grace like: scriptures, prophets, ordinances, prayer etc. We are expected to receive and make use of all these gifts of grace to demonstrate our faith in Christ. But Paul is pointing out that just because we make use of all the gifts Christ has freely given, doesn't mean we should boast that we save ourselves. But it also doesn't mean we don't have to make use of what Christ has given us.
Therefore, we demonstrate our faith in Christ by "making use" of the free gifts of grace Christ has already given us.
"If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: (New Testament, 1*John, 1 John 1:6")
"He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him. He that saith he abideth in him ought himself also so to walk, even as he walked." (New Testament, 1 John, 1 John 2:4-6)
"For this is the love of God, that we keep his commandments: and his commandments are not grievous." (New Testament, 1 John, 1 John 5:3)
"These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God. And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us: (New Testament, 1 John, 1 John 5:12-14)
We demonstrate our love and faith in Christ by obedience and making use of Christ's grace and means He has given us. Christ still makes the first move. Christ gives the means first, then we make use of them to demonstrate our faith and love. Then we have the assurance of salvation.
"No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day." (New Testament, John, John 6:44)The Father draweth all men. But not all will be drawn. LDS have no problem with God making the first move to "initially rescue" and "initially save" us. Then we manifest or faith and love of Christ by obedience as we progress towards "final perfection in Christ". If we demonstrate our faith by making use of the means provided (ordinances and commandments), we can be declared perfected in Christ."All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.(New Testament, 2*Timothy, 2 Timothy 3:16-17)
The Man of God has already been "initially rescued" but only "may be perfect" if we make use of the doctrine, reproof, correction, and instruction in scripture.