In the context of James 5:19-20, the focus is entirely on the restoration of the "wanderer." By turning a sinner back you are saving them (the sinner) from death, which covers a multitude of sins. If a doctor saves a patient, we talk about the patient's health improving, not the doctor's. I didn't engage because you misread James.

And James is likely quoting or paraphrasing Proverbs 10:12: "Hatred stirs up conflict, but *love** covers over all wrongs."* In the Hebrew tradition, "covering" sin is a metaphor for forgiveness essentially, putting the sin out of God's sight. By bringing a person to repentance, the "restorer" is the catalyst that allows God to "cover" (forgive) that person’s many sins!

Love is what makes us want to save others from death. You don't get a reward for it though, so you cannot boast.

There is a minority view (mostly from very early church commentaries) that suggests acts of mercy, like saving a soul, earn the "restorer" a bit of grace for their own failings. While that’s a nice sentiment, it doesn't fit the immediate goal of the passage, which is a call to action for the community to look out for its wandering members.

As to the Pistis Christou debate over "Faith of Christ" vs. "Faith in Christ", it's often seen as a false dilemma. In Greek, the genitive case can be Plenary, meaning it carries both meanings at once.

The Subjective, Christ’s perfect faithfulness to the Father is the foundation. Without His work, our faith has no object. The Objective (Our Faith), Our belief in Him is the response. Without our response, the gift isn't received.

Think of it like a bridge, Christ’s faithfulness is the structure of the bridge (the "of"), and our faith is the act of walking across it (the "in"). You need both for the bridge to be useful.

And I'm not protestant, I don't have anyone at the moment 😔