The important term Missio Dei (Mission of God) needs a biblical foundation. The sending of God by God is a foundational motive in the New Testament. Even at the very beginning of salvation history, shortly after creation, God became the first missionary. In Jesus, God is the missionary par excellence, and in the Holy Spirit, God is the most successful missionary. Mission is part of the nature of God, and therefore mission can only be described holistically and in a manner that transforms human mission into the image of God's mission. In three chapters three important themes regarding the Missio Dei are discussed: 1. The recent history of the term in missiology; 2. the biblical and systematic foundations; 3. the debate between the Western and Eastern wings of Christianity over the ""filioque,"" that is the question, whether the Holy Spirit was sent by the Father alone or by the Father and by Jesus, His Son. Prof. Dr. theol. Dr. phil. Thomas Schirrmacher, PhD, ThD, DD, is professor of the sociology of religion at the State University of the West in Timisoara (Romania), Distinguished Professor of Global Ethics and International Development at William Carey University in Shillong (Meghalaya, India), as well as president and professor of ethics at Martin Bucer European Theological Seminary and Research Institutes with branches in Bonn, Berlin, Zurich, Innsbruck, Prague, Istanbul and Sao Paolo. Schirrmacher has held guest professorships and has given special lectures at universities on all continents. Schirrmacher is chair of the Theological Commission of the World Evangelical Alliance (WEA), director of the International Institute for Religious Freedom (Bonn, Cape Town, Colombo) and Ambassador for Human Rights of WEA; the WEA represents churches with 600 million members altogether. He also is a member of the board of the International Society for Human Rights. Schirrmacher regularly testifies in the German parliament and other parliaments in Europe, as well as in the EU in Brussels, the OSCE in Vienna and other international bodies. His has written 102 books; three of his newest books are Fundamentalism, Racism, and Human Trafficking. He has earned four doctorates, in missiology and ecumenical theology, in cultural anthropology, in ethics, and in sociology of religion, and received two honorary doctorates from the USA and India.