Matthew 25:35-40
34“Then the King will say to those on His right, ‘Come, you who are blessed of My Father, inherit the kingdom prepared for you from the foundation of the world.
35‘For I was hungry, and you gave Me
something to eat; I was thirsty, and you gave Me
something to drink; I was a stranger, and you invited Me in;
36naked, and you clothed Me; I was sick, and you visited Me; I was in prison, and you came to Me.’
37“Then the righteous will answer Him, ‘Lord, when did we see You hungry, and feed You, or thirsty, and give You
something to drink?
38‘And when did we see You a stranger, and invite You in, or naked, and clothe You?
39‘When did we see You sick, or in prison, and come to You?’
40“The King will answer and say to them, ‘Truly I say to you, to the extent that you did it to one of these brothers of Mine,
even the least
of them, you did it to Me.’
I'm pretty sure giving medical assistance, or simply stopping to help someone up who has fallen while trying to escape a shooter/bomber/etc will qualify as doing unto Jesus as noted above. For me, it is less about being able to sleep at night and more about living what I believe. Though, I don't have the mad first-responder skills someone like
@wsfiredude and others here, do.
Surprisingly, though, in an emergency, it doesn't take being an EMT/paramedic/nurse/doctor to be able to do a lot of good medically. Just knowing basic first aid will allow you to help a lot of people and put you in probably the top 95% of people when it comes to knowing what to do. I've been there/done that a time or two (not in a shooting, of course) and was amazed how no one else knew to do simple things like asking people questions to help keep them from going into shock, elevating feet when necessary, putting direct pressure on a wound to control the bleeding, etc.