As people living in this world created by God we are called to believe in Jesus Christ as our Savior, and we are also called to obey the law of God, that is to love God and to love your neighbor as yourself. (Mark 12:30-31)

Both the law and the gospel are good, yet the key to understanding how we grow in Christ is to see the law and the gospel in proper relationship to one another. Both are vital to our growing in holiness, for in becoming more holy we are in fact becoming more like our Savior, Jesus, who perfectly kept the law of God and is holy. 

Let’s put growing in Christ in the context of the gospel first. The first thing that must happen in your life before you can grow in Christlikeness is that you must believe in Jesus Christ as your Savior. You must believe that Jesus died for your sins according to the Scriptures (1 Cor. 15:3-4). At the moment you believe in Christ you are united to him in his life, death, burial, and resurrection and Jesus is united to you.

To understand this more fully let’s explore how the New Testament refers to believers in Christ. It is usually not with the word Christian. In fact Christian is only used three times. The more common way the New Testament talks about believers in Christ is to say we are “in Christ” or “in him” or some other slight variation of this - this is used over 200 times to refer to believers in Jesus. We call this our union with Christ. Galatians 2:20 states this fact very well. The Apostle Paul writes:

^“I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.” - Galatians 2:20

It is essential for us to think about ourselves this way. Christ dwells in us, and we dwell in Christ the moment we believe in him. The question for us as we live the Christian life is, “Do I think of myself this way?” This is the most important thing about us. We must remind ourselves of this constantly; day by day, hour by hour, and minute by minute, each and every day because our union with Christ is the foundation for growing in Christ and living a godly and holy life. 

In light of our union with Christ it is important to understand that we are sanctified by God’s grace and not by our obedience. For without faith in Christ we have no power to obey God’s law (Hebrews 11:6). For it is the power of Christ working through the indwelling power of the Holy Spirit that provides the ability to live a joyous Christian life of obedience. 

It is important to remember our union with Christ is the source of all our fruitfulness. Jesus has cleansed us of sin and given us a new nature so he may use us. Unless we continue to draw on our faith in Jesus, we can do nothing of spiritual importance (John 15:5). This transforms how we treat our spouse, our children, our family, and everyone we come in contact with as grace and love would characterize our relationships.

This is where the law of God comes in. As a believer who has faith in Christ and therefore is in union with him, we now have the power to live a life of holiness and grow in Christ. It is in this way and with God’s law as our guide that we know what ought to characterize our conduct as his children. This is where loving God and loving neighbor comes in, as well as the expression of these two commandments into the Ten Commandments (Exodus 20). 

We must be careful to keep things in the proper order. Our godly living and good works come about as a result of our faith in Christ. In our unbelieving or natural state, or in the flesh as the Bible calls it, we have no power to obey God’s law and do God’s will. We do not obey God’s law in order to come to Christ - to think this is to get the gospel backwards - or to put the cart before the horse you might say.

Rather the Bible teaches we believe the gospel in order to gain Christ, and in so doing we gain all the resources and riches of grace in Christ Jesus, along with his indwelling power through the Holy Spirit to obey and live a joyous Christian life. So you see both the gospel and the law are essential aspects of our growing in Christ.