One of my earliest memories is from when I was in preschool. I was four years old and attending Hickory Grove Presbyterian Preschool, where my mom was one of the teachers. Occasionally we would watch movies projected onto the block wall of the basement, and one day we watched the story of “The Little Train Who Could.” I remember feeling sad for the train as his friends made fun of him. I remember feeling anxious as he finally had a chance to prove himself by hauling that big load up that hill. I remember cheering him on in my mind as he chugged, “I think I can, I think I can…” until he finally crested the top. It is
a wonderful story to teach children the values of determination and perseverance. 

But there is a downside to a story like that. The truth is that there are some things we cannot do, no matter how hard we try or think we can. If we stubbornly push ahead anyway, insisting that we can do something when it is impossible for us, we will become frustrated, angry, and eventually, give up altogether. This is especially true when it comes to spiritual things. Because we are sinners, there are some things that we cannot do on our own. We cannot save ourselves.
No amount of effort will ever be enough to merit salvation or pay off our sin debt. We cannot sanctify ourselves either. Some people teach that salvation is by grace, but sanctification is by works. That is a lie. We are sanctified the same way we are saved: by grace through faith in the person and work of Jesus Christ. Instead of always saying, “I think I can,” we need to learn when to say, “I know I can’t.”