Background (earlier in the chapter): Jesus reassures disciples that they do not need to worry about him leaving them – He is going to prepare a place for them and He will send another counsellor: the Holy Spirit.
The Holy Spirit will teach them (25f)
He will give them his peace (27) – foretold in the OT, realised by his death and resurrection
His “going away” is no need for worry – it is all part of God’s plan (28-31)