… ¹⁰ for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation.

Belief and confession are God’s instruments to bring about salvation in a person’s life. In philosophical terms, they are the instrumental cause.
God is the formal or ultimate cause of our salvation, the energy that brings it about; it is entirely according to His purposes and initiation. It simply cannot be any other way. But our faith and confession are instrumental in the whole matter. It is not as though God’s sovereignty trumps the human will and renders it superfluous and non-volitional. Our faith is not the cause of our salvation; God is the cause.

We are not mere robots, automatons, however, whose belief is hardwired by predestination. It is not that believers could simply do nothing other than believe, and non-believers were destined from the beginning to have no choice, and therefore no hope. The Bible clearly speaks against such a notion about the human condition and responsibility (or lack thereof). The coexistence of God’s sovereignty and human responsibility challenges the mind, much the same way as thinking beyond three dimensions does. But we must acknowledge both to be true because the Bible teaches both, and we will resolve this dilemma in our human thinking when we graduate beyond our earthly existence.

Following Romans 9 and 10, where God’s sovereign choice is made clear, we find here the individual responsibility in salvation clearly laid out. Notice salvation is an individual thing (“a person”), and faith and confession are active things a person does (present tense active mood of the verb tense). It is concrete (“with the mouth he confesses”), and it is volitional (“with the heart”). The Jews thought of the heart as a reference to the will, unlike today, where we tend to think of the heart as a reference to the emotions.

What we do in salvation is effective (“resulting in salvation”). These things are defining activities. In the Greek, the verb is used intransitively. This means the focus is on what the person does, not the object of those things. While verse 9 tells us what a person believes (that God raised Jesus from the dead) and confesses (that Jesus is Lord), verse 10 emphasizes the human activities of believing and confessing. A righteous person is the kind of person who believes and confesses; it is what he does that God uses to save him—that is his participation in the matter. And that results in salvation. Salvation is not automatic, nor is it forced. God uses our real faith to bring salvation and righteousness into our lives.

Praise to You, Father, for Your Son, in whom I believe and confess as Lord.