This study of martyreō and its cognates begins with observations on the distribution in the New Testament and continues with earlier usages in Greek literature and the Septuagint. While in early Judaism witness is not yet equated to martyrdom, instances of bearing witness leading to death emerge. The study goes on to define the specific usages in various parts of the New Testament. Witness leading to suffering anticipates the later Christian notion of martyrdom. Some theological conclusions are: (1) witness is about God’s revelation in history; (2) early witnesses sometimes report about events beyond ordinary experience (e.g., the resurrection of Christ); (3) witnessing is prolonged in conjunction to the work of the Spirit; and (4) it is unsurprisingly accompanied by persecution.