Christ's designation for the Holy Spirit in John 14-16, the title connecting the Spirit's specific work of guiding the apostolic church into all truth. John 14:17, 15:26, and 16:13 each use the title. The fullest statement is John 16:13: Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. The Spirit's ministry is specifically truth-giving: He inspires Scripture (2 Pet 1:21), illuminates Scripture to believers (1 Cor 2:10-14), and convicts the world of sin, righteousness, and judgment (John 16:8-11). The promise to the apostles — that the Spirit would lead them into all truth — was fulfilled in their inspired teaching that became the NT. The Spirit of truth still illuminates that same NT for the church across the ages, and the Spirit's witness will never contradict the Scripture He inspired.