Accepting the Atonement

So today I was browsing the good ol' interwebs when I came across the following question:

Help me, general public:
When all you want to do is make someone happy, when their well-being seems to upstage your own, when helping such an individual is all within your realm of desire and nothing seems to accomplish that, and worse if all they say is there isn't anything you can do to help when you know in your gut you can because those gut feelings for others are the only ounces of sincerity we have left in this world, what do you do? How can you fix a gash so it can be made better than it was before?
Any response will be taken into consideration. I'm looking to change and save something worth saving.

Honestly, I couldn't help myself. Maybe I'm just experiencing premature-hyperactive-missionary-mode (I believe the clinical term is PHMM,) but I had to share my thoughts, and the only way I could think to do that was to liken whatever these to people are going through to the roles we play with the savior when we are choosing to accept his Grace. The following is what spewed out:
(Please note that the person I was dumping my thoughts on was LDS, so at least they knew who the crap I was talking about.)

If someone says that you won't be able to help, then you won't be able to.
Not because you are incapable of fixing their problems or taking their pain away, but because in their minds they have already determined that a problem is un-fixable. And when it comes down it, accepting your help isn't something you can make someone do, it is something they have to choose.
It is like the atonement.
*WARNING* Going into missionary mode here.
Christ already suffered for our sins, he has all power, so why aren't we just perfect already? In some ways I think it is because we say to ourselves, "I cannot change, too much damage has been done, I am not fixable." but in Alma 34 it says,
"if ye will repent and harden not your hearts, immediately shall the great plan of redemption be brought about unto you."
that is so powerful, that word, "Immediately."
We are taught in Mosiah 15, "...all those who have hearkened unto their [the prophet's] words, and believed that the Lord would redeem his people, and have looked forward to that day for a remission of their sins, I say unto you, that these are his seed, or they are the heirs of the kingdom of God."
In both these examples, we see that what we need to receive a remission of our sins is to believe that such a remission of sin is possible. And we see that the Lord is true to his word, for in Alma 36, Alma relates,
"And it came to pass that as I was thus racked with torment, while I was harrowed up by the memory of my many sins, behold, I remembered also to have heard my father prophesy unto the people concerning the coming of one Jesus Christ, a Son of God, to atone for the sins of the world.
Now, as my mind caught hold upon this thought, I cried within my heart: O Jesus, thou Son of God, have mercy on me, who am in the gall of bitterness, and am encircled about by the everlasting chains of death.
And now, behold, when I thought this, I could remember my pains no more; yea, I was harrowed up by the memory of my sins no more."
Until Alma remembered the words of his father, and asked Christ to save him from his torment, he was stuck in a state of misery.
Isn't it amazing that something as simple as accepting the help of another is what dictates our very salvation?
So this was a really long, round about way of saying that what you may want to try focusing on first, is convincing your friend that a problem such as theirs IS fixable. I have a feeling that you already have all the tools one would need to help your friend, but that won't do him/her any good if they don't believe it.

After giving this impromptu and unasked for sermon, the thought struck me, "Hey! Isn't that what missionaries are needed for in the first place?"