John 15:13 Greater love hath no man than this, that a man lay down his life for his friends.
John 15. The setting is the upper room. It's the night just before Christ's crucifixion. Jesus is preparing His disciples for what lies ahead. Prior to His prayer of intercession in chapter 17 and the garden scene of chapter 18, in chapters 13-16 Jesus makes it clear to His disciples that He is leaving; that He'll return in the future; that in the meantime they'll face trouble and persecution from a world that hated Him before it hated them; but that He'll send them "another Comforter," the Holy Spirit. He also continually reminds them of the importance of their love not just for Him, but for one another.
John 13:34-35 A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. By this shall all men know that ye are my disciples, if ye have love one to another.
John 15:9 As the Father hath loved me, so have I loved you: continue ye in my love.
John 15:17 These things I command you, that ye love one another.
John 15:13 is a great and well-loved passage of scripture. It is an undeniable and marvelous truth that Jesus Christ set the example for the greatest love when He gave His love for the sin of all mankind the very next day. But when you look at the verse in its context, you realize that it's not so much about the love Jesus has for us as it is about the love He wants us to have for one another.
Verse 12 says, This is my commandment, That ye love one another, as I have loved you.
What John 15 (and the rest of the NT) is saying is that if we are going to make it through this world that has forsaken our God and hates His word and stand strong and let our light shine, we must, through the power of the Holy Spirit, have this kind of love for one another – that a man lay down his life for his friends.
1 John 3:16 Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren.
Philippians 2:4-5 Look not every man on his own things, but every man also on the things of others. Let this mind be in you, which was also in Christ Jesus:
As carnal creatures, it's so easy for us to get wrapped up in ourselves and forget about everybody else. But God would have us live our lives seeking to be a blessing to our brothers and sisters in Christ; doing things intentionally just to be of benefit to others; giving of ourselves on purpose just to help somebody else out, with the expectation of nothing in return.
That's the greatest love. It's the example that Jesus set, and it's the commandment that He gave.