Zoroastrian exegesis consists basically of the interpretation of the Avesta . However, the closest equivalent Iranian concept, zand, generally includes Pahlavi texts which were believed to derive from commentaries upon Avestan scripture, but whose extant form contains no Avestan passages. Zoroastrian exegesis differs from similar phenomena in many other religions in that it developed as part of a religious tradition which made little or no use of writing until well into the Sasanian era. This lengthy period of oral transmission has clearly helped to give the Middle Persian Zand its characteristic shape and has, in a sense, limited its scope. Although the later tradition makes a formal distinction between “Gathic” (gāhānīg), “legal” (dādīg), and perhaps “ritual” (hādag-mānsrīg) Avestan texts, there appear to be no significant differences in approach between the Pahlavi commentary on the Gathas and those on dādīg texts, such as the Vendīdād , the Hērbedestān and the Nērangestān . Since many 19th and 20th century works by Zoroastrians contain an element of exegesis, while on the other hand no exegetical literature in the strict sense of the word can be said to exist, the phenomenon of modern Zoroastrian exegesis as such will be discussed here, without detailed reference to individual texts. 
Veli-Matti Kärkkäinen joined the Fuller faculty as associate professor of systematic theology in 2000 and was named full professor in 2003. He also holds a teaching position at the University of Helsinki as Docent of Ecumenics.
Prior to coming to Fuller, Kärkkäinen served as president and professor at IsoKirja College in Keuruu, Finland. He has taught and lived with his family on three continents: Europe, Asia (Thailand), and North America (USA). He has also lectured and served as visiting professor in various schools around the world. He travels widely and has a command of several languages.
A prolific writer, Kärkkäinen has authored or edited about twenty books in English (and seven in his native language, Finnish), including The Trinity: Global Perspectives (2007), One With God: Salvation as Deification and Justification (2004), and Trinity and Religious Pluralism: The Doctrine of the Trinity in Christian Theology of Religions (2004), as well as more than 150 articles that have appeared in international scholarly journals. He is also the editor of the Global Dictionary of Theology (with William Dyrness, 2008), The Spirit in the World: Emerging Pentecostal Theologies in Global Contexts (2009), and Holy Spirit and Salvation: The Sources of Christian Theology (2010). Currently he is finishing a five-volume series covering all topics of systematic theology titled A Constructive Christian Theology for the Pluralistic World , published by Eerdmans (2013–2017); the first volume is Christ and Reconciliation (2013), the second, Trinity and Revelation (2014), and the third, Creation and Humanity (2015). Kärkkäinen is member of several editorial boards, including the Strategic Initiatives in Systematic Theology series by InterVarsity Press, the Studies in Systematic Theology series by . Brill (Leiden, Netherlands), and is a reviewer for the International Journal of Systematic Theology .
He has participated in a number of working groups of the World Council of Churches, most recently on “Christian Self-Understanding and Religious Plurality,” and has participated in numerous international theological, missiological, and interfaith consultations, including Edinburgh 2010 and the Conference on World Mission and Evangelism of the World Council of Churches (Athens, 2005). His involvement in Muslim-Christian issues includes the Building Bridges seminars . His ecumenical experience also includes long-term participation in several international bilateral dialogues. For years he served as an external examiner for Wales University.