The trinity is central to Christian faith, but many Christian have question about what the Trinity is and why we believe in a trinitarian God. In The Tripersonal God, Gerald O'Collins examines the roots and development of trinitarian belief, drawing on three areas for reflection: (1) testimony to the tripersonal God in the scriptures-both the Old Testament background and the teachings of Paul and the gospel writers; (2) the development of trinitarian doctrine from the second-century writers and the early councils of the church through medieval theology and modern challenges; (3) major trinitarian issues of today, such as naming the Trinity, the distinct personal existence of the Holy Spirit, and trinitarian imagery. A comprehensive, contemporary inquiry, The Tripersonal God illuminates the historical and scriptural roots of belief in the Trinity and clarifies contemporary trends in trinitarian thought.