The special service for which the ministry is designed is the preaching of the word. The obligation to spread the knowledge of Christ is shared, to some extent, by all Christians. The effectual call of the Holy Spirit, by which any man is brought to repentance and faith, imposes on him an obligation to show forth the praises of him who hath called him out of darkness into his marvelous light; to let his light shine before men, that they, seeing his good works, may glorify his Father in heaven; and to hold forth the word of life. Every Christian is bound to do what he can for he conversion of others, and for spreading the knowledge of the truth. But special gifts are conferred on some, accompanied with special obligations. These constitute a special call to the ministry of the word.
During the Saviour's personal ministry he made many disciples: but he did not intrust to them equally and indiscriminately the work of spreading the knowledge of his religion. He sent forth seventy with a special commission to preach the kingdom of God. He chose the apostles to be his immediate attendants and special witnesses, and gave them a commission--"Go preach the gospel to every creature....Go make disciples, teaching them," &c. Preaching and teaching were prominent and important parts of the service required of them. When Paul was made an apostle, the commission to him, as explained by himself, was to preach the gospel: "Christ sent me, not to baptize, but to preach the gospel." The obligation which he felt to perform this service was beyond that imposed on ordinary Christians, and was exceedingly pressing: "Necessity is laid upon me; yea, woe is unto me if I preach not the gospel" (1 Cor 9:16). With him, to preach the gospel was not to utter a proclamation in a brief sentence; but at Troas he preached to a late hour of the night. In his ministry teaching was conjoined with preaching, and included in it: "Whereunto I am ordained a preacher and an apostle, a teacher of the Gentiles in faith and verity" (1 Tim 2:7).
The obligation of particular men to give themselves to the ministry of the word was intended to be a perpetual arrangement, and not confined to the ministers appointed by Christ in person. Timothy was specially appointed to this service, and was commanded, "Preach the word; be instant in season, out of season; reprove, rebuke, and exhort, with all long suffering and doctrine" (2 Tim 4:2). "Make full proof of thy ministry" (2 Tim 4:5). "Neglect not the gift that is in thee" (1 Tim 4:14). A special gift and a special obligation are here clearly recognised, and the duty to be performed is clearly preaching, in the comprehensive sense in which teaching is included. Paul had committed the gospel to Timothy; nor was the succession to cease in him. "The things which thou hast heard of me, the same commit thou to faithful men, who shall be able to teach others also" (2 Tim 2:2). Special ability and special obligation to preach and teach were to be perpetuated in men, separated to the service from the body of Christ's disciples.