What are the three functions of the believer?

The three assignments that define the purpose of a believer's life are priesthood, ambassadorship, and ministry. Priesthood defines the believer's relationship to God (1 Pet. 2:5–9). Every believer is a priest with the right to represent himself before the throne of grace (Heb. 4:16) and is called to live face-to-face with God. This private function is exercised through prayer (Heb. 13:15; 1 Thess. 5:17–19), the study of the Word, staying in fellowship (1 Cor. 11:28–32; 1 John 1:7–9), and growing in the grace and knowledge of the Lord (2 Pet. 3:18).

Ambassadorship defines the believer's relationship to unbelievers (2 Cor. 5:17–20). Believers are appointed by Christ to the ministry of reconciliation and have a duty to the unsaved (Acts 1:8), urging men to be reconciled to God. As personal representatives of the Lord Jesus Christ, believers are to reflect Him by action and word (John 13:35; 17:23; 1 John 3:18).

Ministry defines the believer's relationship to other believers (1 Cor. 12:7, 11; Rom. 12:1–8). Every believer is called to be a servant to every other Christian, using a sovereignly bestowed spiritual gift to build up and strengthen the Church. Believers are exhorted to concentrate on how to stimulate and encourage one another toward love and good deeds (Heb. 10:24–25).