John 1:7

John the Baptist was the first of many witnesses to the light that John the Apostle identified in this Gospel (cf. John 4:39; John 5:32; John 5:36-37; John 5:39-40; John 8:18; John 10:25; John 12:17; John 15:26-27; John 18:13-18; John 18:37). The Apostle John frequently used courtroom terminology in his Gospel to stress the truthfulness of the witnesses to the Light. John the Baptist bore witness to the light of God’s revelation but also to the person of the Light of the World (John 8:12). This Gospel stresses the function of John the Baptist as a witness to the light. The writer often emphasized something by simply repeating it, as he did here with the word "witness." The other Gospels also identified John the Baptist’s origin and character in their introductions (Matthew 3; Mark 1:1-8; Luke 1:5-24; Luke 1:57-80).

John the Baptist’s ultimate purpose was eliciting belief in Jesus (cf. John 1:35-37). That was also John the Evangelist’s purpose in writing this book (John 20:30-31). Consequently John the Baptist’s witness is an important part of the argument of the fourth Gospel. It was not immediately apparent to everyone that Jesus was the Light. Both Johns needed to identify Him as such to them.

"Since the Reformation, theologians have viewed saving faith as simultaneously encompassing three components-notitia, assensus, and fiducia. In notitia the individual becomes aware of the conditions, promises, and events that constitute divine revelation, especially the events surrounding God’s consummate self-revelation in Jesus Christ. In assensus the individual expresses objective confidence in the truthfulness of these claims (Romans 10:9; Hebrews 11:3; Hebrews 11:6; 1 John 5:1). In fiducia the individual places his or her personal trust in Jesus Christ. Central to this threefold model is a single key assumption: Faith, as presented in the New Testament, necessarily entails the recognition and acceptance of specific, objective content." [Note: Timothy Paul Jones, "The Necessity of Objective Assent in the Act of Christian Faith," Bibliotheca Sacra 162:646 (April-June 2005):150.]