In the Acts of the Apostles, we have the coming of the Holy Spirit to indwell and baptise believers into "one body," by uniting them to Christ the Head, and to one another. This work of the Holy Spirit has been going on ever since in those who have believed on our Lord Jesus Christ to the saving of the soul. At Pentecost they were all filled with the Holy Spirit, and began to speak with tongues as the Spirit gave them utterance. Peter too was filled with the Holy Spirit, and preached the gospel; and the remainder of the book gives us the various actings of the Holy Spirit who had come down in consequence of the accomplished redemption-work of our Lord Jesus Christ. Besides filling saints for the service and praise of God, we trace the Holy Spirit's Godhead, personal actings, and hatred to sin; His sovereignty, power, holiness, and truth. The Gospel was preached not only to the Jews but also to the Gentiles, and the servants of God, principally Peter and Paul, were strengthened and filled with the Spirit to set forth a crucified, risen, ascended, glorified, and coming Saviour with abundance of blessing to souls. It was a time of the Spirit's power, which gave no quarter to selfishness and covetousness. The record of it too is of the Spirit, for it magnifies God, and honours our Lord Jesus Christ, and the authority of scripture.
We have referred already to the epistles of the apostle Paul, and have given instances in proof of the inspiration of God in his writings. It is well, however, to remember, that our Lord Jesus repeatedly spoke to him from heaven as to what he should minister to the saints; but we may notice on other occasions the way in which he so constantly points to the Lord and honours Him as such. For instance, in the second brief Epistle to the Thessalonian believers, he speaks of Him as the "Lord Jesus Christ" ten or eleven times; in Philippians 1 he speaks of Him as Lord or Christ seventeen or eighteen times, and always with reverence and honour; and he seems in all his epistles to write in such a Christ-exalting way, that he is not able to write many verses without turning to Him. Can anything more clearly demonstrate the work and inspiration of the Holy Spirit?
Though Peter's line of instruction to the saints is very different from Paul's, yet when Paul addresses the Ephesian saints, or Peter the converted Jews when scattered, they are both so filled with the love of God, that before they begin their communications to them, they lift their hearts in praise, and say, "Blessed be the God and Father of our Lord Jesus Christ." Peter's line as well as Paul's is Christ; but Peter, especially in his first epistle, points to an unseen Saviour as the fountain of "joy unspeakable and full of glory;" though such too "greatly rejoice" in Him, who has accomplished such a work in His death and resurrection, as gives us title to an incorruptible inheritance reserved in heaven for us, while we are kept for it.
John, however, who recognised the workings of infidelity even in his day, is so conscious of the apostolic ministry being the word of God, that he declares it to be the true test of vital Christianity. He says, "We are of God; he that knows God hears us; he that is not of God hears not us." (1 John 4:6.)
Though James addresses his letter to the twelve tribes, he recognises "beloved brethren" among them, and ministers to them as such, ascribing their being begotten of God to "the word of truth;" and though not entering upon the special truths of Christianity, he instructs, quotes from the prophets, and enjoins them to practical piety in the prospect of the coming of the Lord. With James, the man who says he has faith can only show it by his works. The more the epistle is pondered, the more clearly the Spirit's teaching can be recognised in it.
Jude, though he treats of the apostasy, tracing it from its root to its full development and judgment, of which Enoch prophesied, exhorts the faithful to contend earnestly for the faith which was once delivered to the saints, to keep themselves in the love of God, praying in the Holy Spirit, and building up themselves on their most holy faith, while seeking the good of others, and looking for the mercy of our Lord Jesus Christ.
All these Epistles, though written at different times, and by different instruments, tell us of unity of purpose and object.