Another way to talk about intercession might be to say that because the life we have is a share in God’s life, when we pray on behalf of another, we are creating a space for God to use that life as is most appropriate, according to God’s light, not ours. Because of our shared nature with God, in this space our life becomes God’s life: God’s tears, God’s offering, God’s power. We set God free to work his mysterious love in ways that we should not care to seek to know, if we are rightly focused on God. Some people wake each night to devote a specific amount of time to this conscious offering of their lives on behalf of the world, to make a space, however humble, where some small fragment of human suffering can perhaps find a little respite and peace.
There are as many ways of intercession as there are moments of life. Intercession can become deep and habitual, hidden even from our selves. There is nothing exotic about such practice. What matters is the intention that creates the space and the stillness. Even something as simple as refusing to anesthetize the gnawing pain in the pit of your soul that is a resonance of the pain of the human condition is a form of habitual intercession. To bear this pain into the silence is to bring it into the open place of God’s infinite mercy. It is in our very wounds that we find the solitude and openness of our re-creation and our being. We learn to go to the heart of pain to find God’s new life, hope, possibility, and joy. This is the priestly task of our baptism.
From: Maggie Ross: The Space of Prayer, III
I do recommend reading Maggie's whole three-part (so far?) series on prayer - there are some profound and lovely things there, and a deep understanding of the contemplative way.