whom not having known you love; in whom, though now you don't see him, yet believing, you rejoice greatly with joy unspeakable and full of glory--
They said to Jesus one day, "What must we do, to do the works of God?" And Jesus said, "This is the work of God, just believe on him who he has sent" ( John 6:28 , John 6:29 ). And so God has done the work; God's part, all of this was God's part. Then He finally gets to your part: through faith, just believing and trusting that work of God.