Real love will always be expressed, sometimes in surprising ways.  John wrote this verse to introduce the very unusual Passover evening when Jesus washed His disciples’ feet.  It was His final teaching to His trainee apostles before He ascended to be with Father God in heaven.  And He knew that He would be crucified within 24 hours.  The prospect of death always concentrates the mind.  But instead of thinking about Himself, Jesus focussed on serving His disciples and started with an unforgettable physical demonstration of servant leadership.  

But that was strange: after all, He was their Master and they were His pupils, learning from Him.  They served Him and would never have expected Him to serve them.  In becoming a servant, doing the menial job of washing dirty feet, Jesus showed how much He loved them (John 13:4-10).  As Jesus personally took each filthy foot and washed it with His own hands, His slave-like service breathed out the language of love and set the pattern for love in the church which is always marked by sacrifice.   But He never ceased to be the Master.  He was teaching that to love is to serve - a lesson that would be pivotal for growing His kingdom through the years to come.
 
The cross was for their sakes (and for ours – 2 Corinthians 5:21), and they needed to know that it was no mistake or accident.  Rather, it was love – deliberate, pre-planned, timed, voluntary and sacrificial.  There is no true love without selfless service.  Love that does not abandon itself for the benefit of the loved one, is not love at all.  Jesus wanted His disciples and us to learn that lesson.  Without His sacrificial love on the cross there could be no redemption of the world: without our sacrificial love, the church cannot be built, nor can Jesus be glorified.
 
Love is a choice to willingly obey those who have the right to command you (Colossians 3:22-24), and willingly serve those who have no right to expect it (Philippians 2:5-7).  So, a very practical part of following Jesus is to serve people for His sake.  Opportunities for love-choices are scattered through every day.  It is right to serve: it is the normal Christian life.  As Jesus said in John 13:14-15: “Now that I, your Lord and Teacher, have washed your feet, you also should wash one another’s feet. I have set you an example that you should do as I have done for you”.   So, we need to make sure that we recognise the opportunities to love people through service and take thought-through sacrificial action that will demonstrate that we are following Jesus – because we love as He loved (1 John 4:10).