If we pray for peace we're effectively telling ourselves- and the world- that peace is something we don't have- and thereby making the absence of peace our reality. We're saying peace may be attainable some time in the future but isn't available now. And the universe which has a very literal mind- gives us the reality we're projecting out into it.
What we need to do is own our peace, to live in it as if we already possess it- because that way we create peace around ourselves.
You pray for peace and you're saying war is the norm- and that just reinforces the unpeacefulness. Celebrate peace and you're saying peace is the norm and that creates and radiates peacefulness.
The prayer called St Patrick's Breastplate has it right- not asking for something to be given but taking possession of it now.
I bind unto myself today
God's power to guide me,
God's Might to uphold me...etc
This way of thinking applies to any kind of activism, any kind of desiring. Don't pray for what you want, live it.
I didn't think this out for myself. I got the essence of it from a channeling of the US social activist Jane Adams in Talking with Twentieth Century Women by Peter Watson Jenkins and Toni Ann Winninger.
PS. This is a second attempt at this post. During the process of revision I thoughtlessly deleted a comment plus my response to it. Sorry.