The thesis is divided into four chapters. Chapter I treats the theme of mixed marriages in the Old Testament. Chapter II treats the theme in the New Testament, particularly in the passage of I Cor. 7:12-16 which I believe contains the most compact theology of mixed marriages in the New Testament as taught by Paul. Chapter III treats the theme of mixed marriages in the early church. Chapter IV, I will reflect on and draw conclusions from the previous three chapters, approach pastorally and try to establish some pastoral guidelines for what the church should do.