Shared Prayer

I was recently asked why are we using a prayer calendar, why a month of prayer, and what is their purpose? Aside from the obvious discipline building exercise of following a calendar, for me it is like comparing the effect of 5 + 5 + 5 to the exponential effect of 5 x 5 x 5. Recently I read a devotional by Martha Graybeal Rowlett which explains it well.
“Shared prayer adds power to the work of intercession. Christians dare to believe that God needs and wants to hear our prayers, our compassionate intercession for one another and for our world. Through our prayers for one another, circumstances are changed and the work of the kingdom is done. An individual may feel overwhelmed by the needs of the world, or even the needs of a single congregation, but there is strength in numbers. Individuals gain courage for the task of intercession when the community prays together, aware of Christ’s presence among those gathered in his name. And the person for whom prayers are offered feels the added force of multiple prayers.”
If there is power in our prayers (and certainly we all agree on that), then there is exponential power in the prayer of the community that prays together, both as they encourage believers and touch the ear of God.