Eastern Orthodox Christianity is a strongly biblical church. A large portion of the Daily Office is made up of either direct portions of scripture (Psalms, lections) or allusions to scriptural passages or themes (hymnography such as that contained in the Octoechos, Triodion, Pentecostarion, etc.) The entire Psalter is read in the course of a week (twice during Great Lent). The entire New Testament (with the exception of the Book of Revelation) is read during the course of the year, and numerous passages are read from the Old Testament at Vespers and other services.