Summary: Our Joy is full when we obey Christ and we do that by remaining growing through Him
Demi-Lee Brennan had a liver transplant at age 9. She faced a life on anti-rejection drugs like every other transplant patient. Nine months later, however, her red blood cells were being attacked by her own white blood cells. It was as if her body was treating them as if they were an invader. Something radical had to be done to save her. On a whim her doctor decided to take her off the anti-rejection medications and she got better. What happened was she had changed blood type. She was no longer O-negative, like her parent’s but had taken on the donor’s O-positive type.
Now, at 15, she is totally off any immunosuppresion and, although she has to retake every childhood shot she’s ever had. She is normal. The fact that a young boy had died to give Ms. Brennan a new life isn’t taken lightly. She says, "I’m probably the most grateful person because that has saved my life and gave me a chance to fulfill my life. I just want to live it the most I’ve got for them and to show them that I’m so grateful." 
Radical transformations do happen. Not only when a donor’s blood cell invades a person’s marrow but also spiritually when God calls us to new life through His son, Jesus.
John 15 is part of the long discussion between the Last Supper and Jesus’ arrest. The disciples are upset. They have heard one of them will betray Jesus. Peter’s heard he will deny Jesus. Jesus has told them he is going away and although this has been tempered with a promise to return it is still a dark time for those who are with their Lord.
Let me share with you the hopeful and positive truth in these verses.
• As we listen too, obey and rely on Jesus’ teaching we are thinned and ready for a bigger harvest.
The word used describes either a taking off a branch or thinning of a vine so that better fruit might develop. Both are at work here. Judas has been pruned away from the vine. And the other disciples will find themselves put to the test as Jesus dies and they await the glory of that Easter.
Jesus’ words thin us out today. His teaching, leading, and instruction have the force of centering our lives on Him and off of the other interruptions the world offers us.
• We bear fruit. In fact, we bear "much" fruit.
Jesus contrasts this fruit with the nothing that dead branches bear. They are useless. Our lives are spoken united to the Vine. Our health, purpose and the very fruit we bear is directly linked to the health of that union. The result of NOT being joined to Christ isn’t as nice such branches are tossed away; they wither, and are burned as firewood.
• We are privileged of asking and receiving anything we desire and we’re promised it will be given.
We are not given a spiritual American Express card on which we can charge whatever we fancy. This promise is given within a very real context. What we ask for, when we are joined too and remain attached to the vine will always be that which is in line with the desires of Jesus for us. If we seek fruit that is in line with God’s will we can rest assured God will grant it. It isn’t because we ask the right way, use the special, secret words, or are more deserving; we are gifted simply because our God is gracious and wants Christ and our joy to be filled.
To remain in Christ is really simple. "9As the Father has loved me, so have I loved you. Now remain in my love. 10If you obey my commands, you will remain in my love, just as I have obeyed my Father’s commands and remain in his love." This isn’t rocket science. Loving Jesus equals doing what he says. What does he tell us to do? Look at verses 12 and 13, "12My command is this: Love each other as I have loved you. 13Greater love has no one than this, that he lay down his life for his friends." To love is to put the desires of another above your own, all the time. It is an act of the will not an emotion one falls in-and-out-of. Love is also acting in the best interest of the other regardless of whether or not that is what they want.
And here is the reason behind this teaching, "11I have told you this so that my joy may be in you and that your joy may be complete." Jesus’ joy is in us. He enjoys us as we remain in Him. Jesus likes us. And the joy that we so often search for is found as we obey him.