Wayne Grudem is research professor of Theology and Biblical Studies at Phoenix Seminary in Phoenix, Arizona. He holds degrees from Harvard (AB), Westminster Theological Seminary (MDiv, DD), and Cambridge (PhD). He is the author of more than a dozen books including the bestselling Systematic Theology. Erik Thoennes is associate professor of Biblical Studies and Theology at Biola University/Talbot School of Theology, California, USA. His is also a pastor at Grace Evangelical Free Church in La Mirada, California. He holds degrees in philosophy, systematic theology and evangelism from Central Connecticut State University (BA), Wheaton College Graduate School (MA, MA), and Trinity Evangelical Divinity School (PhD). Brianna Smith is Adjunct Professor of Theology at Biola University, La Miranda, California.