What is the significance of Jesus saying, "You will be my witnesses" (Acts 1:8)?

In Acts 1 we learn, as nowhere else, the fact of the Lord's continuance on earth after His resurrection for forty days, during which He was seen of His disciples, making known to them His valedictory commands, and speaking to them of the kingdom of God. Also the special question which, when gathered together, they preferred before Him as to the time of the restoration of the kingdom again to Israel. This elicited that momentous word of His designed, without setting the kingdom aside, to direct their hearts to the coming in of the Holy Ghost — an unseen spiritual power — with all that it carried with it to faith, signifying that it was not Israel in revived glory and a Messiah in displayed power that He would set before their hearts, but a refused and departing Saviour bringing in a time of testimony, in which the Holy Ghost and they were to be His witnesses, as also He had Himself said before He suffered. (John 15:26-27.) Of the One hated without a cause the Holy Ghost and they were to be the witnesses; all this had faded from their minds, and the Lord's latest breath on earth was expended in reinforcing it upon their souls (Acts 1:8), expressing as it does the whole character of the period until He return. We all know that the first word with which He met His disciples in resurrection at the beginning of these forty days was, "Peace unto you," expressing their portion in Him; and now, in the closing moment before He ascended, He clearly suggests that His portion would be in them ("Ye shall be witnesses unto me"), and the Holy Ghost's advent would be the incoming of power unto this specific end. Nor is it unimportant for us to see that it is as the refused One of men He is received up, and it is as associated with this refused Man, the Christ of that glory into which He has entered, that they go forth joint-witnesses with the Holy Ghost. And, indeed, we may fittingly go much further, for it is in fact the key-note of the whole period of His absence. He went away as the refused Man, and is that refused Man today. He constituted His disciples, in the presence and power of the Holy Ghost, His witnesses in the scene of His refusal, even unto the uttermost part of the earth, and it goes without saying that just such, if up to our calling, is what we are to Himself this day.

These words explain the situation with divine precision and unspeakable grace. It is not yet to be the displayed kingdom which belongs to the age and world to come. Now it is a question of testimony in the power of the Holy Ghost, with Whose mission and presence it is bound up. They were to be witnesses of Christ, not yet reigning with Him, but His witnesses, as rejected yet risen, despised of men, especially of the Jews and Jerusalem, but on the point of being exalted of God in heaven, and witnesses of Him — for all is of grace — both in Jerusalem and in all Judea and Samaria and to the end of the earth. Compare with this beginning of the Acts the end of Luke's Gospel, where the risen Saviour commands that repentance and remission of sins should be preached in His name among all nations beginning at Jerusalem: 'And ye are witnesses of these things. And behold, I send the promise of My Father upon you; but tarry ye in the city of Jerusalem until ye be endued with power from on high.' It is not baptism here, but vital blessing, repentance to life and remission of sins sealed with the Holy Ghost. All has its place and propriety, but the better thing it was the lot of the beloved physician to indite under the inspiring energy of God, Who was (in honour of His Son's person and work) giving life and liberty with the Spirit's seal to all that believe the gospel: its source the grace of God, its righteous foundation the cross of Christ, its character of life His resurrection; its formative object His heavenly glory; and its power the Holy Ghost sent from above.

The Lord had been speaking of the kingdom of God; their minds however still ran on the restoration of the kingdom to Israel. In this they were like the two going to Emmaus, though now they knew that He was risen. Their question gave to the Lord the opportunity of indicating what was to be the programme for the opening dispensation, and we see again just what we saw in Luke 24; the Centre of the programme is not Israel but Christ. The coming of the Spirit would mean power, not that the apostles should be restorers of Israel, but "witnesses to Me" — witnesses to Christ to the utmost bounds of the earth. The four circles of witness, mentioned at the end of verse 8, supply us with one way of dividing up the book. We begin with the witness in Jerusalem, and until the end of Acts 7 we are occupied with that city and Judaea. Then in chapter 8 comes Samaria. In Acts 9 the man to carry the Gospel to the Gentiles is called; and in Acts 13 the mission to the uttermost parts begins.

But they would receive power ("dunamis"), not authority, as the word "power" means in v.7, but vital energy, through the coming of the Holy Spirit upon them. This would enable them as witnesses to Him, beginning at Jerusalem, but spreading out to Judea and Samaria, then the far reaches of the earth, -- a wonderful contrast indeed to a kingdom confined to Israel.

WITNESSES

The disciples having been with the Lord from the beginning were very special witnesses. They had heard with their ears, and seen with their eyes, and with their hands had handled the Word of life, they bore witness to what they had heard and seen, the Holy Ghost being the power by which they did it. We may thank God for their witness, for we now can have fellowship in those things that they heard and saw, and have recorded for us. But we are not excluded from this witnessing, for we may keep our Lord's company and speak of that that we learn experimentally with Him. A witness may preach, but not every preacher is a witness. A witness is one who has been impressed by what He has seen and heard as he has kept company with the Lord. 2 Corinthians 3:18 explains it, "We all beholding the glory of the Lord … are changed into the same image from glory to glory, even as by the Spirit of the Lord;" and Stephen was the outstanding example of it, not when he exposed the obdurate hearts of the Jews, but when he prayed, "Lord, lay not this sin to their charge, " when they were battering him with stones in their murderous hatred.

For this witnessing the Holy Ghost is indispensible. He has come from Christ in glory, and He bears witness to His glory, and makes Him real to us whom having not seen we love. The revelation to us of His victory over death by resurrection, and His exaltation to the Father's throne has set all things for us in a new and true light, and it is that light shining in and shining out that constitutes us witnesses to and for Him. The secret of witnessing is Company with Him.

The last words that the disciples heard from the lips of their risen and ascending Lord were, “ Ye shall be witnesses unto Me . . . UNTO THE UTTERMOST PART OF THE EARTH .” What amazement must have filled their Jewish hearts when, after the cloud of glory had received Him out of their sight, they began to realize the vastness of the sphere in which they were to witness for Him. They were eager to tell of His glory to Israel, for hitherto their hopes and affections had been confined within that narrow bound; but now in their hearts were to be enlarged at the coming of the Holy Ghost to embrace the world; they were to speak of the most blessed Person, exalted to the most glorious place, to the greatest possible number of men; for not a needy sinner beneath the sun had to be denied the favour of hearing the Word, and upon all had to be pressed the rightful claims of Christ.

But this coming of the Spirit has still another aspect. Before His ascension, Jesus bids His disciples "wait for the promise of the Father, which, says He, ye have heard of Me. For John truly baptized with water, but ye shall be baptized with the Holy Ghost not many days hence. When they, therefore, were come together, they asked of him, saying, Lord, wilt Thou at this time restore again the kingdom to Israel? And He said unto them, It is not for you to know the times or the seasons, which the Father has put in His own power. But ye shall receive power, after that the Holy Ghost has come upon you; and ye shall be witnesses unto Me, both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth" (Acts 1:4-8). Here Jesus promises his disciples a "baptism" of the Holy Ghost. This recalls the prophecies of Joel and John the Baptist and as their prophecies are connected with national deliverance, they ask whether He would then restore the kingdom to Israel. Jesus replies that the time for this was hidden in the Father's counsels, but that as the immediate effect of the Spirit's coming, they would receive power, and should be witnesses for Him in all parts of the earth. There are, then, three things here named, the baptism of the Holy Ghost, the giving of power to the disciples, and the fitting of them to be witnesses for Christ.

In the next chapter we read that "when the day of Pentecost was fully come, they were all with one accord in one place; and suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it [or they] sat upon each of them; and they were all filled with the Holy Ghost, and began to speak with other tongues as the Spirit gave them utterance" (Acts 2:1-4). This was, clearly, the fulfilment of Christ's recent words, that they should "be baptized with the Holy Ghost not many days hence." It was also, no doubt, the coming of the Spirit spoken of in the Gospel of John. Indeed the three things named by Christ in the previous chapter — the "baptism" of the Spirit, the conferring of "power" on the disciples (of which the miraculous gift of tongues was the first manifestation), and the fitting of the disciples to witness for Jesus "unto the uttermost part of the earth" — were all simultaneous in their performance, and were all results of the same event, the sending of the Holy Ghost to take his abode in the world. But though simultaneous, they must be carefully distinguished from each other.

First, as to the promise of power. "And, behold, I send the promise of My Father upon you: but tarry ye in the city of Jerusalem, until ye be endued with power from on high" (Luke 24:49). Similarly, "But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto Me both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth" (Acts 1:8). In these two passages we have the distinct promise of our Lord, after His resurrection, that the disciples should receive the Spirit, promise of the Father, and should thus be endued with power from on high, which would enable them to be witnesses, bearers of the gospel, first in Jerusalem and then in ever widening circles until they reached the uttermost ends of the earth. They were to tarry at Jerusalem until they received this power. And we know they did this, continuing in expectant prayer from the time of our Lord's ascension until the day of Pentecost; and the power came in connection with the promised gift of the Spirit.

The apostles returned to Jerusalem with those words ringing in their ears, "Ye shall be witnesses to Me." How did they set about it? Did they appoint a committee to gain "adequate knowledge of the field" of operations, so that "scientific calculations" might be made, and "sound strategy" and "statesmanlike plans" decided upon? No, they simply betook themselves to their knees in the spirit of little children, and when they found themselves endued with power from on high they at once commenced their witness to Christ, boldly utilising each opening for testimony as it presented itself to them. Though they had been called by the Lord to positions of authority in the church of God, analogous to the position of an army officer when compared with a common soldier, yet they recognized that it was not theirs to plan the campaign, but to do what they were told. They had supreme confidence in their great Commander; His "adequate knowledge," His "strategy," His "plans" they accepted as sufficient; and they were content to proceed under His direction whether directly or providentially conveyed to them.

It is very well to keep in mind that it is to be done in His name. When we speak to souls of Christ we should speak as His representatives. He came into the world; "God was in Christ reconciling the world to Himself," and if we are to speak at all of the Saviour we do so as representatives of Him. How the grace of our God is unveiled! They had to start in Jerusalem itself. The Lord revealed Himself to the disciple that had sinned the most; the Gospel had to go to the city that had sinned the most, the city where He had been crucified. There was forgiveness for that city, and for the worst men in that city. If the worst can be forgiven, then, you see, none ever need despair. So the Lord instructs them; how their hearts must have been overjoyed and blessed as they listened to His words. We have in the first chapter of Acts the last words they hear from His lips: "Ye shall be witnesses to me, … to the uttermost part of the earth." Then He says, "Tarry ye in the city of Jerusalem until ye be endued with power from on high." Do not attempt to speak for Me until the Spirit of God comes, for the work of God can only be done by the Spirit of God; the Spirit of God is the only power in this world for God, and if we attempt to serve Him in our own strength, the result will be disaster. I do not suppose Satan cares two straws about a man preaching the Gospel if he is doing it in his own strength and wisdom. So He told them of the only power that can carry them through and enable them to serve the Lord rightly; that is why 3,000 were converted on the day of Pentecost.