They are certainly related, but they are not the same, and I should add that never should Christian perfection be conceived as preparing the way for justification by faith. The question requires a definition of both concepts and a clear understanding of how we are saved. We need to look at Christ’s work outside us and in us.
1. CHRIST’S WORK OUTSIDE US
Here is a fundamental idea when we study the concept of salvation: God decided to save us without asking for our opinion. Long before God created us, He formulated a plan to restore us to fellowship with Him (Rom. 16:25, 26; Eph. 1:9, 10). In our absence the Lord made decisions that would affect us: The Son of God would offer Himself to become human (John 1:14, 15); would minister to suffering humanity to reveal God’s infinite love (1 John 4:9); would take our place and die, bearing our sins as our substitute (Rom. 5:8; 1 John 3:5; 4:10); after being buried and resurrected, He would ascend to heaven to be our high priest (Heb. 4:14, 15). His sacrifice would remove the barrier of sin that separated us from the Father, making it possible for us to return to Him (2 Cor. 5:19, 21). God did all of this one-sidedly, without consulting us.
God also decided to send the Holy Spirit to entreat us to accept His gracious saving work (John 16:13). In all of this our obedience or lack thereof played no role (Rom. 5:8; 1 Peter 3:18). It was all God’s doing! Unilaterally God determined that His Son will come back to earth to take His people to the Father’s house (John 14:1-3). He also established that at the Second Coming He would transform us (1 Cor. 15:51-54) and remove us from an environment characterized by sin, suffering, and death, and would finally create a new heaven and a new earth (Rev. 21:1, 4). All of this free of charge! The only thing required from us is to accept the gift of salvation through faith in Christ—the righteousness of Christ imputed/credited to us. At that moment we are freed from the enslaving power of sin (Gal. 6:15; Col. 1:13, 14).
2. THE WORK OF CHRIST IN US
Based on what I have said, I would suggest that Christ’s work in us is not what saves us but that it is rather a manifestation of His power, through the Spirit, procuring to restore in us His image. It is the Spirit that enables us to grow into the likeness of the Son of God while at the same time we are constantly depending on His atoning work for us. This is precisely what Christian perfection is—we are daily growing in grace in order to be like Him (1 Peter 2:1-3, 21; 1 John 2:6), while concurrently placing our faith exclusively in Christ’s forgiving grace for the assurance of our salvation (1 John 2:1, 2).
These two aspects of the Christian life should not be confused with each other. There are many reasons to justify our need to develop a character like Christ’s, but probably one of the most important is to make our service to others more effectual (1 John 4:11; 1 Peter 2:12). Then unbelievers will see our “good behavior in Christ,” and they will be ashamed (1 Peter 3:16, NIV). Peter adds, “Each of you should use whatever gift you have received to serve others” (1 Peter 4:10; NIV). This is our response of gratitude, prompted by the Spirit, to God’s loving grace that grants us eternal life through His Son.