Part of John 15 says, "Every branch in me that does not bear fruit He takes away, and every branch that does bear fruit He prunes, that it may bear more fruit. Already you are clean because of the word that I have spoken to you."
A branch can't bear fruit on its own ... it needs the vine. God is the vine and we are the branches: Both work together for good. Without one, the other cannot grow.
In John 15:16, the Lord says He chose you. You did not choose Him. You have been appointed to bear fruit. Our lives as Christians are His doing, and we are blessed to be chosen. This is a big choice as those who are called are to serve in His name and bring others to Christ. While you choose to accept Christ into your heart, He called you by name.
John 15: 5-8
“I am the vine; you are the branches. If you remain in me and I in you, you will bear much fruit; apart from me you can do nothing. If you do not remain in me, you are like a branch that is thrown away and withers; such branches are picked up, thrown into the fire and burned. If you remain in me and my words remain in you, ask whatever you wish, and it will be done for you. This is to my Father’s glory, that you bear much fruit, showing yourselves to be my disciples.”