How long has it been since you read a theology book? I lament that reading theology does not appear to be a priority among missionaries. In Mere Christianity, C .S. Lewis comments on the importance of theology and doctrine:
. . . if you have once accepted Christianity, then some of its main doctrines shall be deliberately held before your mind for some time every day. That is why daily prayer and religious reading and churchgoing are necessary parts of the Christian life. We have to be continually reminded of what we believe. Neither this belief nor any other will automatically remain alive in the mind. It must be fed. And as a matter of fact, if you examined a hundred people who have lost their faith in Christianity, I wonder how many of them would turn out to have been reasoned out of it by honest argument? Do not most people simply drift away?
Mere Christianity, Kindle loc. 1601.
Even missionaries can drift and need to remind themselves of what they believe. So reading theology should be part of a healthy diet for lifelong learning. Evangelical missionaries will want their theology grounded in Scripture. The “Foundations of Evangelical Theology” series edited by John S. Feinberg is an excellent resource for theological reading. The series published by Crossway Books now has 9 volumes with a few more forthcoming.
The latest volume in the series, Against the Darkness: the Doctrine of Angels, Satan, and Demons by Graham A. Cole was published in 2019. Dr. Cole serves as Dean and Professor of Biblical and Systematic Theology at Trinity Evangelical Divinity School. Cole’s approach to Systematic Theology is called “contextualized affirmations” as distinct from the classic approach of making doctrinal affirmations followed by Scripture references in parentheses. He describes his approach:
A complementary method is that of contextualized affirmations. A key text which mentions angels is not simply cited but is quoted, placed in its context in its literary unit in its book in the canon in light of the flow of redemptive history before doctrinal implications are considered. An advantage of this method is that it can show why the chosen text is described as a key one. Paying attention to the flow of redemptive history is important to both methods. – Against the Darkness, 20.
The book contains nine chapters: (1) Introduction; (2) Angels, Their Kinds, and Heavenly Activity; (3) Angels: Their Activity on Earth with Individuals and Nations; (4) Satan, the Malevolent Spoiler; (5) Demons, the Devil’s Entourage; (6) Jesus, Christus Victor; (7) Spiritual Warfare; (8) the Destiny of the Darkness and the Victory of the Light; (9) Conclusion. There are five excursuses: the Nature of Spirit; Angelophany; Genesis 6:1-4 and the Methodological Questions; How to Test the Spirits; and the Archangel Michael and the Man of Lawlessness. There are three appendices: the Creation Manifold; Angels, Iblis, and Jinn in Islam; and Creeds, Articles of Faith, Catechisms, and Confessions. Chapters 2-8 include a section titled “Implications for Belief and Practice” following the discussion of keys texts.
The chapter on spiritual warfare is of special interest to missionaries. Cole provides a working definition:
So as a working definition, let me define spiritual warfare as that aspect of our common struggle as Christians against the machinations of malevolent spiritual creatures that are intent on thwarting God’s redemptive plan for his human creatures. -165.
After surveying key NT texts and evaluating several contemporary spiritual warfare models, Cole provides his perspective he calls “Toward a Biblically Defensible Model for Spiritual Warfare.” He highlights our union with Christ, the armor of God (Ephesians 6:10f), prayer, and humility among other things. He warns against the fanciful and any belief that is “text-less.” A “text-less” belief is one that is not based on a biblical text or at least consistent with a biblical text. He sees no biblical justification for addressing Satan or demons directly. In a parenthetical statement Cole writes:
(I was once asked at a seminar whether I would speak directly to the devil. I replied that we were not on speaking terms.) – p. 186.
Overall, Against the Darkness provides the reader with a doctrine of Angels, Satan, and Demons that is grounded in the Bible. While there may be places where one would like the author to say more, Cole is committed to avoiding speculation where the Scripture is silent. The entire Foundations of Evangelical Theology series is well worth reading to feed and remind us what we believe lest we drift away.