You are only seeing 1/3 the story

I believe that this text [Exodus 17; Israel vs. Amalek] offers a biblical corrective to what often looks from the outside as though the “Joshuas” of this world (that is, politicians, pastors, missionaries, and so on) do all the work. This account reveals where the true power to win comes from. In very memorable form, this story illustrates how the three parties that are always involved in biblical intercessory prayer (God, intercessor, and the party that is being interceded for) relate to each other.—Standing in the Breach, page 59