In the face of another act of gun violence, James Martin, S.J. has shared a prayer that I find useful. I’m reprinting it here so that you can read it without the interruptions that appear on the original site.
I come before you,
after another shooting.
I am sad, God.
So I ask you
to receive into your loving care the souls of those who were killed,
to care for those who were wounded or hurt in any way,
to console the family members and friends of those who died or were wounded,
to strengthen the hands of the rescue workers, medical professionals and caregivers
I pray too for the shooter, as I must as a Christian.
All this makes me inexpressibly sad, God.
But I know that the sadness I feel is your sadness.
It is the same sadness your son expressed
when he wept over the death of
his friend Lazarus.
I am tired, God.
I’m tired of the unwillingness to see this as an important issue.
I’m tired of those in power who work to prevent any real change.
I’m tired of those who say that gun violence can’t be reduced.
All this makes me tired.
But I know that the tiredness I feel is your tiredness.
It’s the same tiredness that Jesus felt after his own struggles against injustice
that led him to fall asleep on the boat with his disciples.
I am angry, God.
I’m angry at the seeming powerlessness of our community to prevent this.
I’m angry at the selfish financial interests who block change.
I’m angry that these shootings happen at all.
But I know that this anger is your anger
It’s the same anger Jesus felt when he overturned the tables in the Temple,
angry that anyone would be taken advantage of in any way.
Help me see in these emotions your own desire for change.
Help me see in these feelings as the way that you move me to act.
Help me see in my reactions your pushing me to do something.
Because I know this is the way you move people to action.
And I know that you desire action.
For Jesus did not stand by while people were being hurt.
He plunged into their lives.
So help me to answer these questions:
How can I help?
How can I fight against gun violence?
How can I urge my political leaders to enact change?
How can I help people understand that this is
an issue about life?
I am sad over the loss of life,
tired of excuses for the loss of life,
and angry that we are paralyzed by the loss of life.
Turn my sadness into compassion.
Turn my tiredness into advocacy.
Turn my paralysis into the freedom to act.
to be compassionate,
and to act,
as your son did,
Almighty God. 
 James Martin, S.J., “Sad, Tired and Angry: A Prayer in the Face of Gun Violence,” America Magazine, October 02, 2017, accessed October 02, 2017, https://www.americamagazine.org/faith/2017/10/02/sad-tired-and-angry-prayer-face-gun-violence.