This book looks into the liturgy of the Mar Thoma Church. The Mar Thoma Church claims to be Eastern and Reformed. An enquiry is made into the liturgy of the Eucharist to look into the the prayer for illumination. The measuring rod to determine the Eastern and the Reformed nature is the Eastern fathers such as Gregory Nazianzen, Athanasius, St. Basil, etc., and the Reformer John Calvin. The prayer for illumination as laid out in the Eucharistic liturgy of the Mar Thoma Church is compared to the prayer for illumination in the Syrian liturgy and the Genevan psalter. Some observations are made and, accordingly, conclusions are drawn. Based on the conclusions, some implications are given for the Mar Thoma Church.