Mark Batterson says,
I think Jeremiah 1:12 is one of the greatest promises in Scripture: "I am watching over my word to perform it." Most stress is caused by a lack of trust. We don't trust God to do His job. Why? We're control freaks. But here is the problem: we can't do what God has called us to do. Only God can do it. And He will do it. He is watching over His word to perform it.
Take a deep breath. Now let it out. That is the effect Jeremiah 1:12 has on me. Takes all the pressure off of me! I constantly remind myself that I cannot do it. And in some strange way, it helps me relax. It also keeps me in a place of raw dependence upon God. And that is the most peaceful and powerful place on the planet.