As a Christian, you have everything you need to be what you ought to be. Spiritual maturity is not a process of gaining things that you did not have when you became a believer.

For example, consider a newborn baby. It isn’t born without arms, and then gets them later. It’s not a pollywog. It doesn’t develop into a frog. When a baby is born, it has all the physical equipment it will ever have. In fact, the older we get, the more stuff we lose!

When you were born in Christ, you were made spiritually whole and have all you will ever need to become mature. It’s only a matter of development until you function in a mature way. You have everything you need—there is no lack, you are complete in the Lord.

However, a Christian can arrest his development and even permanently damage himself by sinning. As damaging as sin is, we must acknowledge that we sin, not because we lack anything, but because we do not appropriate what we have.