John knew that his readers knew about the Last Supper and the Lord’s Supper. It was already well-established in the churches that people remembered Jesus in bread and wine. So John told the rest of the story, with Jesus washing his disciples’ feet as an act of loving humble service, and getting them ready by teaching and prayer for life after Easter – in the time when he would not be with them in body, but when his Holy Spirit would be by them and within them, continuing the presence of God on earth in a new way.
He said that the Spirit would lead them into all truth, reminding them of all that he had said to them. Both sides of this need to go together. God didn’t stop leading and speaking to his people at the end of the New Testament, but everything he’s said since is tied to what Jesus said through Scripture and while he was here. We face issues and questions undreamt-of in the time of Jesus. Our world changes fast, and our faith isn’t meant to apply only to the questions and knowledge of the ancient world. We need to be able to take account of new knowledge and new opportunities, and Jesus’ words in particular are our greatest resource for doing that. But the Spirit is still leading us into new truth for new situations – consistent with what’s been before, but not just restating it. Finding that truth isn’t an exact science. It needs attention to scripture, the world and the Spirit – and a dose of humility to recognise that we will sometimes get it wrong.
Perhaps that’s why, before teaching about the role of the Spirit in leading the church into ever richer truth, John tells us of Jesus’ new commandment – love one another.
That’s not new in itself, but there is something new about it, as Jesus goes on to qualify that love as ‘just as I have loved you.’ There have been plenty of calls to love in Israel’s history, but now for the first time the disciples have seen love with a human face – Jesus. Now, for the first time, there is a perfect model of what a loving life looks like. Now we know more fully than ever what it means to love.
Jesus sets that before his ‘farewell discourse’ about the future life of the Spirit. When people see Jesus-like love from his church, they will know that Jesus is real and living in his church. If that love is not there, then none of what Jesus is going to talk about in the coming chapters will make any difference.
Without love, even all the truth God will show the disciples will not bring life. Let us love.