Mature people walk in the Lord. This means at least two things. First, believers walk just as they have received Christâ€”by faith. They received Christ by faith, so they are to walk and continue with Christ by faith. When they received Christ, they trusted His righteousness and death to cover their sins and to make them acceptable to God. Therefore, they are to walk continuing to trust His righteousness and death. It is His righteousness and death that continues to cover their sins and make them acceptable to God. They have nothing within themselves to earn, merit, deserve, or make God accept them. They can do nothing and they can possess nothing that will secure the approval of God. The believerâ€™s only acceptance before God is Christ, trusting the righteousness and death of Christ.
Second, believers received Christ as Christ Jesus the Lord. That is, when believers received Him, they accepted Him as the true Messiah and Lord from heaven; they accepted Him as the Lord of their lives. Therefore, believers are to walk before Him as Lord; they are to continue walking and serving Him as the Lord of their lives.
There are three things in particular the believer is to do.
1. The believer is to be rooted and built up in Christ. There are two pictures in this statement.
The picture of being rooted is that of a tree. The believer is to be like a towering tree that has its roots deeply planted in the ground. The ground provides strength against wind and storms and nourishment for life. The believer is to draw his nourishment and strength from Christ.
The picture of being built or constructed is that of a building. Jesus Christ is the foundation for life, the only sure foundation. Therefore, the mature believer is a person who has built his life upon Christ.
The point to note is this: the emphasis upon a strong attachment and a flow of nourishment and life from Christ to the believer. That is, the believer is to walk in a continuous, unbroken communion and fellowship with Christ. His life and mind are to focus upon Christ without interruption, drawing all nourishment and strength from Him. This is critical, for there is no other permanent nourishment or strengthâ€”not that lasts forever and imparts eternal life to the human soul.
2. The believer is to walk established in the faith just as he has been taught. The word “established” means to be firm, stable, holding fast and not letting go. This shows the utter necessity for strong teachers in the church. When believers have strong teachers, they are to learn all they can about the faith and hold fast to it.
3. The believer is to walk overflowing with thanksgiving. Christ Jesus the Lord has done so much for the believerâ€”so much that flows on and on, never ceasing, not even for one moment of any day. Therefore, the believer is to learn to walk in an unbroken spirit of thanksgivingâ€”a thanksgiving that overflows in praise to the Lord moment by moment throughout the day.