Jesus, in John 14:1, says, "Do not let your hearts be troubled." The Greek word here can be translated as "agitated." Like the "agitator" in a washing machine that goes back and forth, back and forth.
This verse implies that we have a responsibility, that we can "let" the agitator into our hearts. We can allow troubledness to dwell in our inner, spiritual home. When we do this it's like saying, "Trouble, I give you permission to make yourself at home in me."
How can we stop Trouble at the doorstep of our spirit? Jesus' answer in John 14:1 is: "Believe in me." Given the context of John chapters 14-15-16 we see that "to believe" is not mere intellectual acknowledgment, but intentional engagement and abiding-connectedness to Jesus. To believe is to abide. Real belief abides. Real belief takes up residence in a certain "abode." "Belief" always abides somewhere. In this case it's either:
a) "Trouble" makes its home in me, by my permission; or
b) I abide in Christ, giving Christ permission to set up home within me.
There are "works" of Trouble and works of Christ. "Troubledness" has causal effects and deeds. Implications. Manifestations.
Christ-belief also has consequences. If you trust Jesus (the antecedent of the conditional statement we are making), then you will do the works Jesus does and even more (the consequent of the conditional statement; therefore when the antecedent is affirmed, there follow the Jesus-like consequences.). It looks like this.
1. If I trust Jesus, then I will do what Jesus does and more.
2. I trust Jesus (in the sense of abiding in Him).
3. Therefore, I will do what Jesus does and even more.
In John 14:24 Jesus says, "Anyone who loves me will obey my teaching. My Father will love them, and we will come to them and make our home with them." The agitator is unwelcome in the Father's home. Troubledness has no place in a trusting heart.
My recent book is: Praying: Reflections on 40 Years of Solitary Conversations with God.