“I still have many things to say to you, but you cannot bear them now. When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He will glorify me, for he will take what is mine and declare it to you. All that the Father has is mine; therefore I said that he will take what is mine and declare it to you.” (John 16:12–15, ESV)
“I’ll explain it to you later, but right now we need to deal with something more urgent.” It is so easy in our conversations with others to get ahead of where we should be and lose sight of what it most important at the moment. Jesus knew that this was not the time to tell His disciples all that He had to say or all that was to happen to them or through them in the days and years to come. He knew that there would be a time for this to be shared and He knew who would share it accurately. If He told them then and there all that He had for them it would be way too much, so much that they could not bear it. As a result He metered out to them just what He needed to in order to assure them that the Father had not lost control, that Jesus had not failed, and that the Spirit would indeed come to them so that they might continue in what they were called to do.
This was not the time for all of the “what about” questions or panic. Jesus was intent on steeling them for His leaving and building hope in them for the coming of the Spirit. Having told them that He was not finished and that there was still things to say, Jesus assured His disciples that when the Spirit came the Spirit would come as truth just as Jesus had. Just as we read in John 1:14 and 17 that the Word (Jesus) became flesh and was full of grace and truth, so also will be the Spirit when He comes. There is no diminishing of truth with the Spirit, for the Spirit is fully God speaking with full and accurate authority. Jesus did not speak for Himself, but spoke what He had heard from the Father. Similarly the Spirit would (and does) not speak for Himself, but speaks what He has heard also.
Included in the things spoken was even to be words about the things that are to come. As Scripture has fully be given to us we see that the Word of God does indeed contain much that has already happened, but also that to for which we are still waiting to see completed. For us who are in Christ it includes our entrance into the presence of God. It also includes what Scripture declares concerning the last days. It speaks about how God works in and through believers, and as it was unfolded it even includes how God sent the gospel to the whole world (and not just the Jews). Peter said that there was no prophecy that was on man’s invention, but men who were moved by the Holy Spirit spoke from God (2 Peter 1:21), and this is what the Spirit did for Jesus’ disciples who were eyewitnesses to all that happened and who Jesus had just told them would hear more later.
The Father had given everything into the hands of the Son, and the Spirit took what was His and declared it to them who recorded it for us. Now we have that message to share in the power of the spirit who works to convict/convince them of its truth. Paul wrote of this process in Romans chapter 10. “For “everyone who calls on the name of the Lord will be saved.” How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching? And how are they to preach unless they are sent? As it is written, “How beautiful are the feet of those who preach the good news!” But they have not all obeyed the gospel. For Isaiah says, “Lord, who has believed what he has heard from us?” So faith comes from hearing, and hearing through the word of Christ.” (Romans 10:13–17, ESV)