"he will keep your life"

I'm getting a little nervous with our walk coming up in a few weeks now. And it didn't help to see a front page Tribune story the other day about a young couple who were attacked and killed, without apparent motive. Not an image I want in my head, though I suppose I should admit the possibility. Then, this morning in church, we sang these lines (written by an acquaintance of mine from the Reba Place neighborhood):

I want to walk with you, Jesus
Show me the road and I'll go
I look to the valleys, I look to the hills
I look to the sky and I know
It brought to mind the beginning of Psalm 121, so I looked it up.

I lift up my eyes to the hills.
From where does my help come?

My help comes from the LORD,
who made heaven and earth.

He will not let your foot be moved,
he who keeps you will not slumber.
The Lord is your keeper;
the Lord is your shade on your right hand.
The sun shall not smite you by day,
nor the moon by night.
The Lord will keep you from all evil;
he will keep your life.