I have a job where I often, almost daily, feel like I'm not smart enough to be doing it. I often think one of these days someone is going to find out I'm not as smart as I should be. I have this fear of complete failure. Working with brilliant physicians and scientists in my work gives me an inferiority complex. So when I am driving to yet another work presentation where I am trying to convince doctors and scientists that I know the best ways they should teach, I am often dealing with some adrenaline and anxiety. It is in those moments that I pray and then chant over and over that simple phrase, "Just do your best and let God do the rest." I don't just chant it like a memorized childhood bedtime prayer. I actually think about the words I am saying. What I'm really saying is that I am so limited. My knowledge and abilities are God given. I cannot rely on my own smarts, or strength, or even charisma. I need to just do what I can and believe that God will do it for me. He's been doing it for me for years! Look at where he has brought me!
Ok, there is no exact Bible verse that states this. However, this sentiment is certainly present in a number of Bible verses.
Colossians 3:23-24 (NIrV)
"In a race all the runners run. But only one gets the prize. You know that, don’t you? So run in a way that will get you the prize."
1 Corinthians 9:24 (NIrV)
"I can do all this by the power of Christ. He gives me strength."
Philippians 4:13 (NIrV)
All of these verses point to the importance of using all of our God-given abilities to do our best. There is one issue I do have with my chant... at what point do we allow God to do the rest? When we are exhausted? When we don't feel smart enough? When we are sick? Really, we are supposed to allow God to work from the very beginning. Before we do your best, we should commit our effort to the Lord. He promises to accomplish His purpose through us.
"Commit to the Lord everything you do. Then he will make your plans succeed."
Proverbs 16:3 (NIrV)