Which now of these three, thinkest thou, was neighbor to him that fell among thieves?
And he said, He that shewed mercy on him.
Then said Jesus unto him, Go, and do thou likewise.
Telling the parable about a guy beaten and left for dead, pushing things to an extreme, illustrates the principle very clearly. But in our lives, typically the situation is not so obvious, the story not so ironic as it was in the Savior's parable: mostly, our opportunities to show compassion are really very ordinary, and I think that sometimes we don't even realize it when we do it. That's just... what you do.
It was in reading a midwifery text book when I was pregnant with my third (I love birth, and had already read the usual "over the counter" books, so I'd found something "prescription strength"), that I realized how, in the Church, we often do compassionate things as a matter of course, and we don't recognize the value of what is being done. I read how student midwives are advised that new mothers need a number of things to have a well-developed support system: contact with women who have recently given birth and other experienced mothers, who will coo over her baby and share the wisdom they have gained when she needs it, as well as assistance with meals and possibly other day-to-day chores in that first time after the baby is born. In fact, after reading this section of the book my thought was, "Oh! What all new moms need is a Relief Society!" Nearly every item on the list was something that is routinely checked on by the Relief Society.
The Savior has asked us to do the things which He has done, to bear one another’s burdens, to comfort those who need comfort, to mourn with those who mourn, to feed the hungry, visit the sick, to succor the weak, lift up the hands which hang down, and to “teach one another the doctrine of the kingdom.”
-Barbara Thompson, And of Some Have Compassion
These small things, little kindnesses we do for our friends and acquaintances and the strangers around us, are acts of compassion. Many of us do compassionate, merciful things, often without even realizing it, simply because it's "the right thing to do". All of us, I have no doubt, could learn to do still better at following the Savior in this way: everything the Savior does is focused on One. One hurting heart, one need filled, one pain eased. There is so much hurt in the world, it can sometimes feel impossible and overwhelming, but we don't have to fix it all. We just follow His example and do what we can for one person at a time. The Savior loves us one by one. He heals us individually, one by one. And he sends us to be His assistants, one by one, to one person at a time.
Compassion and mercy are twins - not identical, but so close that they can sometimes be tough to tell apart. Mercy is "the compassionate treatment of a person, greater than what is deserved, and it is made possible through the Atonement of Jesus Christ. ... Every blessing we receive is an act of mercy, more than we could ever merit on our own. (source)" Christ's specialty is mercy, fueled by His perfect compassion, born in His perfect love. And He delights in teaching us to feel that same depth of compassion, to act in that same merciful way: to become like Him.
There is one who understands, who sympathizes. He was misunderstood, rejected, knew supreme loneliness, was poor and had not a place to lay his head, suffered anguish and conflict of mind.
He can give pardon and bring peace.
The specialty of the Savior is mercy.
And he requires that we be specialists in mercy.
Marion D. Hanks, My Specialty is Mercy, emphasis original