Growing in the Lord is different from growing physically. Once you reach the age of fifteen, you can't go back to the age of fourteen physically. Once you reach the age of eighteen, you can't go back to the age of seventeen physically, obviously.
We start thinking that once we have learned a certain thing about the Lord, or grown in a certain area, we will never be weak in that area again.
Many people go to a revival, a convention, or a camp where God does something in their life. The tendency is to think, "Now I know that I will never fall of be weak in that area again."
Unfortunately, that is simply not true. Growth in the Lord is like muscle development. You have to continue to exercise that muscle in order for it to stay strong. If you do not, it will get flabby and weak. Many of you who work out with weights know that if you don't continue to work out, you can't keep pumping the same amount of iron.
Many Christians are like an elderly person with a disease whose mind doesn't work very well. You may have seen people with a sickness that causes them to revert to thinking or acting as if they were children or infants. That's what a lot of Christians look like. They're "mature," so they think, because they have been in church their whole life. But, they still drool like a baby, act like a baby, and prove by their very lives that they're very immature.
"Watch out that you do not lose what you have worked for" (2 John 8).Look at this verse carefully. Do not lose what you have worked for. There are some things in Christ that we have to work for if we want them.
Now, we know that salvation is a free gift of God (Rom. 6:23). There is nothing that we can do to earn it without own works (Titus 3:5). We give our whole life to Jesus, and He gives us a brand new heart. He changes our life. We can't earn any of this. There is nothing we can do to be good enough for God.
Once we have received the free gift of salvation and the new heart and changed life, there are some things that we need to earn and work for if we want them. One of the things that we work for is maturity in Christ. You don't get maturity by praying for it. You do not get maturity by wanting it or hoping for it. You get maturity in Christ by working for it.
You get maturity by working on different areas of your life that God wants you to grow in. That is what becoming a mature Christian is about - learning how to work "with God: using His Word on different areas of your life to help you to grow.
If you want maturity in Christ, you need to decide right now that you are going to be the kind of person who works for it. You have to say, "I don't care how hard it is, or how long it takes, I refuse to be a baby Christian my whole life. I refuse to be a baby Christian even this next year of my life. It is time to grow up."
I encourage you to make that decision as you dive into some prayer time and tell the Lord that you are serious about paying the price. Whatever it takes, no matter how hard you have to work to grow up as a Christian, you must be willing to do it.
About Maturity in Christ by Ron Luce
Excerpt permission granted by Albury Publishing
Ron Luce was the co-founder and president of Teen Mania Ministries from 1986-2015. Ron and his wife Katie dreamed to raise young people who would change the world. 
