Recent anthropological, linguistic, and philosophical studies have significantly increased our understanding of the gift and related phenomena, such as hospitality and charity. While their results can only very carefully be applied to historical theological sources, they do resemble classical discussions on neighbourly love, the administration of sacraments, the handing over of tradition, free will, and God's mercy. In this book, Risto Saarinen studies Martin Luther's understanding of the gift and related issues, such as favours and benefits, faith and justification, virtues and merits, ethics and doctrine, law and Christ. The historical motivation behind this focus consists in the insight that Luther both continues and criticizes the classical, medieval, and Humanist discussions regarding the differences and parallels between gifts and sales. This historical understanding paves the way towards an adequate systematic theology of the gift.