I think that to answer the OP and frame this discussion in the Calvinist light the WCF puts it in, we must again look at the Covenant perspective here. The relation of faith and works can be tricky but from the right Covenental perspective it makes sense. The elect are brought into the Covenant of Grace on two grounds, objective and subjective Justification.
Objective Justification is when God in His tribunal declares the sinner to be just in his sight because of what Christ has acomplished through His active, living a perfect life, and passive, paying for our sins, rightousness. This pardon doesn’t mean anything to the prisoner until his prison doors our open and he is let free. This is subjective Justification and is where faith comes in. This what is meant by Justification by faith alone, we are subjectivly Justified by faith alone. We are Objectivly Justified by Christ alone through grace alone.
Now this Justified person is regenerated and made alive in Christ, he is a new man. In a larger scope the purpose of redemption, which Justification is a part, is to restore a Covenant people to God. So now this Justified person is part of the Covenant community of God. How you get in (Redemption/Justification) and stay in (Perseverance/Sanctification) is by God’s grace alone. But being in the Covenant of Grace requires us to preform good works of love in graditude to what God has acomplished for us. So in this light good works have no forensic or debt paying element to them, we don’t have the problem of linking good works to faith because we see them both in light of the Covenant of Grace.
Now because we are still in possession of a sin nature we will fall short of perfection. Some Covenant members will and have commited such greivous sins as to deserve excomunication, which removes someone from the visible Covenant community. This is where the quote from the OP is somewhat refering to. Covenat breakers in scripture have always incurred the wrath of God, thuis is what the OP is refering to. We don’t understand punishments of Covenant members in a forensic or debt paying sense, it seemed that some people were thinking in that way about the wording. As a Covenant member, who is made a member purely by grace, there are ethical obligations in response to grace that are expected of us. That is the foundation of good works.
I hope that clarifies the Confession. It can be confusing to understand what is being is said unless you know the over arching context in which it all makes sense. Catholocism is no different. I must understand the big picture if I am to understand the individual pieces of theology.