It was this same prophet speaking to these same people who explained the role as comforters we all receive when we are baptized, "And now, as ye are desirous to come into the fold of God, and to be called his people, and are willing to bear one another's burdens, that they may be light; Yea, and are willing to mourn with those that mourn; yea, and comfort those that stand in need of comfort" (Mosiah 18:8-9). A main responsibility we have as Latter-day Saints is to help alleviate the suffering of others. We have been commanded to "look to the poor and the needy, and administer to their relief that they shall not suffer" (D&C 38:35). As Latter-day Saints and Christians we have been commanded to, "Bear ye one another's burden's, and so fulfil the law of Christ" (Galatians 6:2).
The miraculous thing is that by mourning with those who mourn and helping other people bear their burdens, our own burdens and suffering are alleviated. The Savior's whole life was spent focused on others but in the act of the Atonement, His will was completely swallowed up in the Father's. The Atonement is an infinitely Other-focused act - it was not done to benefit Himself. In the pre-mortal world, Christ answered the call to act as propitiation for the sins and sorrows of humankind. He performed the greatest selfless act the world ever knew or will know. As we turn our focus outward and serve others without seeking personal gain, we will find the cure for suffering. In doing good to others, we will overcome our sorrows and sufferings. It is not possible to suffer while selflessly serving others. I'm not talking about playing a martyr's role (e.g., "I do so much for other people; I suffer in silence") as we sacrifice for others. There is an attitudinal difference between helping others and feeling, even to a small extent, unappreciated or underappreciated - even in hindsight - and simply serving truly without thought of oneself - without feeling inconvenienced or that we are playing the "Suffering Saint" role.
The problem with playing the martyr's role is that it's exactly that - playing a role, acting, putting up a facade. Being a martyr usually is honorable; playing a martyr is not. Playing a martyr's role is taking upon ourselves the black shroud of victimhood - it is assuming the victim's role and attitude. The only way to feel victimized is to focus on yourself. [Note: There are many true victims in the world; however, there are some people who have been victimized who don't act like victims; you can be a victim without having to feel like a victim. I'm not minimizing any who have been truly taken advantaged of or victimized; I just think that true healing only comes when the feelings of victimization are gone]. However, when we honestly are focused outwardly, inwardly we find peace, comfort, and balance.