Sanctification by Faith
Now the God of hope fill you with all joy and peace in believing, that you may abound in hope, through the power of the Holy Spirit.
Being made right with God is by faith. Growing in grace and holiness is by faith. The Christian life is a life of faith. No formula. No checklists. No programs and procedures. The Christian life is faith in the person: Jesus (John 6:29). We stand on his promises, his victory, and his resurrection power. The how in the Christian life a is moment-by-moment trust in Jesus Christ, the author and finisher of our faith (Heb. 12: 2).
The unity of what salvation is: a single piece, and yet a flowing stream. I became a Christian once for all upon the basis of the finished work of Christ through faith; that is justification. The Christian life, sanctification, operates on the same basis, but moment by moment. There is the same base (Christ’s work) and the same instrument (faith). The only difference is that one is once for all and the other is moment by moment.
The whole unity of biblical teaching stands solid at this place. If we try to live the Christian life in our own strength, we will have sorrow; but if we live in this way, we will not only serve the Lord, but in place of sorrow He will be our Song. That is the difference. The how of the Christian life is the power of the crucified and risen Lord, through the agency of the indwelling Holy Spirit, by faith moment by moment (Rom. 15:13).
This is our calling through the agency of the Holy Spirit. We are not called to serve God just any way, but to know joy and peace in believing.
Francis A. Schaeffer, The Complete Works of Francis A. Schaeffer : A Christian Worldview, Vol. Three: True Spirituality (Westchester, IL: Crossway Books, 1996), 273. [paragraphing mine].