This is an excellent question and is perhaps the most important question in all of Christianity.  The Service for Maundy Thursday has this very idea as its focus.  The word Maundy comes from the Latin word for mandate, or command.  On His last night with His disciples before his betrayal, passion, and death Jesus gave them His Great Commandment: “you must love one another even as I have loved you.”  To our great consternation, He did not leave us with specific instructions on how we should do that.  But what He did leave us was a life lived in Love.  So, Jesus’ life is His manifesto on how to live in Love.  As far as we know, Jesus never wrote a single word of instruction for us.  He lived a life.  And His disciples over the course of some 50 years wrote down what they thought was important about His life and we call those writings the Gospels, or The Good News.  The study of the Gospels is the only way that we have to learn about how to Love the way that Jesus wants us to Love.

I am sure that last paragraph did not define what Jesus’ kind of love looks like in a satisfactory way.  So let me start here, with the word “Love”.  In English we only have the one word for Love.  In Greek, however, which was the language of Jesus day, there are four words that help us to understand what Love is.  Three of those words are used in the New Testament. 

There is a kind of Love called Eros.  This is the kind of love that is denoted primarily by physical, or sexual love.  It is not limited to love-making, but is characterized by the kind of love that takes from another.  The Valentines candy heart that has “be mine” inscribed on it is a perfect example.  Eros is the kind of love that is possessive and jealous.  It is the kind of love that demands fulfillment.  Erotic love is entirely self-centered.  One of the reasons that the Romans persecuted Christians in the early days was because we held “Love feasts” which they interpreted as Erotic but Christians did not allow outsiders to participate in the “feasts” and the Romans were angry about this denial.

Another kind of love is called Phileo, from which Philadelphia gets its name.  It is called Brotherly Love.  Phileo is characterized by friendship and affection.  Another is called Storge’ which is simply Familial love; the love of a parent for a child.

The word that Jesus uses when He talks about Love is Agape’.  This love is called “self-giving love”.  It is a profound sacrificial love that persists beyond circumstances.  What Jesus intends for Christians to do is rather than to take love from each other, to give to each other without limit and expecting nothing in return.  The most amazing example of Agape love is Jesus’ own voluntary sacrifice of himself on the cross for our sake.  The one without sin took upon himself all of our sins, so that we might be made free from sin.

As Christianity became more widely understood in the Roman Empire, the Romans came to understand that we were very different from themselves.  They were free with their bodies and stingy with their money.  Christians were generous with their money but were stingy with their bodies, having only one sexual partner for a lifetime.  Over time, Agape’ Love conquered the Roman Empire, and will someday conquer the entire World.