v18-19 & 21 are talking about Judas. v20 seems out of place. Is it an indirect way of saying that whoever receives Judas, sent by Satan, receives Satan? Perhaps not eternally, but in a given situation when someone like Judas is being influenced by Satan?
v23-25 John is the youngest of the disciples and he’s hanging on Jesus like a kid – great picture of how intimate we can be with Him – and Peter, who’s older, is saying “pssst, get Jesus to tell us who it is” instead of asking himself.
v26-29 Jesus tells them He’s going to show them who it is, then He shows them – and nobody gets it. I know we get the benefit of reading this a jillion times so we do get it, but the disciples are really coming across as doofuses here. I guess what it shows is how much respect they had for Judas, seemingly a really good guy (the most trusted person is assigned to keep the money), so it went over their head. Maybe it also warns us how bad people can be wolves in sheep’s clothing.
v30 I love the double poetic meanings that John gives: just a blunt, “and it was night” – both in time of day and spiritually.
v34-35 The old commandment was to love your neighbor as yourself. Now Jesus increases the threshold greatly: we’re to love with a perfect love just as Jesus loves perfectly. We cannot do that in our own strength, which is why I guess God waited to “up the ante” until He gave us the Holy Spirit.
And THIS is how He says men will know we belong to Him, NOT by doing miracles. Later we’re told that loving one another is a bigger work than miracle. That’s counter-intuitive since it seems that miracles would be a better sign; but I suppose loving some of the people we know IS a true miracle!
v36-38 Just before going up the mountain for Jesus’ transfiguration, He told the disciples that Peter is a rock on which the church will be built – but now He foretells Peter’s denials. That should encourage us that we can fail and still be used by God to accomplish great things.