Answer: Spiritual maturity is achieved through becoming more like Jesus Christ. After salvation, every Christian begins the process of spiritual growth, with the intent to become spiritually mature. According to the apostle Paul, it’s an ongoing process that will never end in this life. In Philippians 3:12–14, speaking of full knowledge of Christ, he tells his readers that he himself has not “already obtained all this, or have already been made perfect, but I press on to take hold of that for which Christ Jesus took hold of me. Brothers, I do not consider myself yet to have taken hold of it. But one thing I do: Forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus.” Like Paul, we have to press continually toward deeper knowledge of God in Christ.
Christian maturity requires a radical reordering of one’s priorities, changing over from pleasing self to pleasing God and learning to obey God. The key to maturity is consistency, perseverance in doing those things we know will bring us closer to God. These practices are referred to as the spiritual disciplines and include things such as Bible reading/study, prayer, fellowship, service, and stewardship. No matter how hard we might work on those things, however, none of this is possible without the enabling of the Holy Spirit within us. Galatians 5:16 tells us that we’re to “walk by the Spirit.” The Greek word used here for “walk” actually means “to walk with a purpose in view.” Later in the same chapter, Paul tells us again that we’re to “walk by the Spirit.” Here, the word translated “walk” has the idea of taking things “step by step, one step at a time.” It is learning to walk under the instruction of another—the Holy Spirit. Being filled with the Spirit means we walk under the Spirit’s control. As we submit more and more to the Spirit’s control, we will also see an increase in the fruit of the Spirit in our lives (Galatians 5:22–23). This is characteristic of spiritual maturity.
When we become Christians, we are given all we need for spiritual maturity. Peter tells us that “[God’s] divine power has granted to us all things that pertain to life and godliness, through the knowledge of Him who called us to His own glory and excellence” (2 Peter 1:3). God alone is our resource, and all growth comes by grace through Him, but we are responsible to make the choice to obey. Peter again helps us in this area: “For this very reason, make every effort to supplement your faith with virtue, and virtue with knowledge, and knowledge with self-control, and self-control with steadfastness, and steadfastness with godliness, and godliness with brotherly affection, and brotherly affection with love. For if these qualities are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ” (2 Peter 1:5–8). Being effective and fruitful in the knowledge of the Lord Jesus is the essence of spiritual maturity.