The disciples were worried by the thought that Jesus would go away, so He reassured them that the Holy Spirit’s presence would be just like having Him with them all the time. They rightly looked to Jesus as their teacher, and maybe wondered how they would be able to remember all the wonderful things He said: but the problem was already solved.
 
God had already planned for His Holy Spirit to live inside everybody who believes in Jesus. He would be a teacher like Jesus and also would enable the disciples to recall everything that Jesus had said. That is why the gospel narratives have so much detail, as though a reporter was there at the time writing it all down. When the time came for the gospels to be written, the Holy Spirit gave the disciples a vividly accurate recollection of what Jesus said and did.
 
The whole Bible was written under the Holy Spirit’s inspiration (2 Peter 1:20-21 ). As He also indwells every believer, He helps us to understand what God is saying when we read the Scriptures. Jesus taught the disciples and continues to teach us as the Holy Spirit helps us. Because He is unchanging, the Spirit’s teaching is consistent with the words of Scripture and the recorded words of Jesus. So these verses give us great confidence that God will speak to us through the Holy Spirit as though Jesus was in the room with us. That gives us all the more reason to invest our time and energy in reading God’s Word and asking the Holy Spirit to help us understand it. So as we read these verses today it is right to ask God to speak to us through His Holy Spirit and show us whatever He wants to teach us.