The title of this section is interesting in and of itself: “The Call to Holiness.” That there is a call and an expected response means something. The faithful life is more than just saying, “I accept You my God as my Lord and Savior.” Actions are expected of us. If I adopt you and move you into my home, it would not be enough for you to call me “Dad,” there are certain behaviors that I would expect from you.
That being said, there is nothing that you can do to win your salvation. Jesus did that. We are “called to God not in virtue of (our) works, but by His design and grace, and justified in the Lord Jesus” and have been made sons and so truly sanctified.
But not Christ, or the disciples, or the early Church Fathers, or the Christian Church for most of the history of Christianity said that was enough. We are called to holiness – to purify ourselves. “You, therefore, must be perfect, just as your Heavenly Father is perfect.” We are to “live as is fitting among saints” (Eph 5:3) and to “put on as God’s chosen ones, holy and beloved, compassion, kindness, lowliness, meekness and patience (Col 3:2). In fact, the New Testament is positively dripping with calls to works and conforming our lives. Though salvation may be freely given, its effects can be lost. We can throw it away. There is no such thing as “once saved, always saved.” The saved are called to something.
However, we will sin. The best among us will stumble and fall. Perfection is not that to which we are called in this life. We can’t do it. If we could, we wouldn’t need Jesus. But our call is in untiring striving. For the rest, we rely on God’s unfailing mercy for His children. If we follow this plan, we will grow in holiness. It is a proven path. One only need look at the history of those carved in stone or wood, or whose images are captured in glass, to know that this is path Christ marked out for us.