Outside of Scripture, no other resource has grown and blessed my prayer life like Matthew Henry’s Method for Prayer. And, if you could only own one resource to help you compose corporate prayers, buy this one. Yes, I realize Ligon Duncan has a “prettier” edition, but the editors have placed all the Scriptural references as endnotes (major fail). The edition I am recommending prints the references inline with the text, and this is helpful precisely because Henry’s book is all about praying the Bible.
The book breaks down into all the major components of Biblical prayer: praise, confession, petitions, thanksgivings, intercessions, etc. Every line is dripping with God’s Word, and Henry helps us to pray from all of the Bible: Ezra as well as Psalms.
If you are just beginning to compose prayers of confession, you could easily take one line from each of Henry’s subsections in his chapter on confession, string them together and you would have a wonderfully logical and God-honoring prayer.