May your spirit and soul and body be kept sound and blameless at the coming of our Lord Jesus Christ. The one who calls you is faithful, and he will do this. (1 Thessalonians 5:23-24)

Would you trust the hospital chaplain to do open-heart surgery on you? How about a carpenter doing your dental work? Would you welcome that? Whenever we need a job done, we want a specialist who knows exactly what they’re doing. It makes no sense to assign a task to someone who is completely unqualified for it.

When it comes to our Christian growth, you and I simply aren’t up to the job. But thankfully, the job isn’t all up to us (1 Thess. 3:12-13). We have a highly qualified, divine Specialist working both with us and within us to do it. He is Jesus Christ, the supremely Faithful One, whose Spirit begins the work of salvation in us and is certain to bring it to completion one day (Phil. 1:6). Sanctification—our growth in holiness—is not as much about beating ourselves into submission and developing our spiritual disciplines as it is about letting Jesus Christ’s life grow in us. We must trust him as he brings our faith to maturity. Certainly, we are involved in the process; but the Faithful One is the actual guarantee that the job will be finished properly.