Romans 10:10 - Matthew Poole's English Annotations on the Holy Bible

With the heart man believeth; in the former verse confession was set first; in this, believing. Faith indeed goes before confession; I believed, says the psalmist, and the apostle after him, therefore have I spoken; yet our faith is discerned and known by our confession. Unto righteousness; i.e. unto justification. This phrase may be expounded by Romans 4:5, or Romans 9:30. With the mouth confession is made unto salvation: our adversaries the papists make great use of this text, to prove that good works, as confession, &c., are the cause of salvation; whereas confession is required here, not as the cause, but as the means thereof. The apostle makes faith here to be the cause, as well of salvation, as justification; because confession of the mouth, to which salvation is here ascribed, is itself an effect or fruit of faith; and so, according to that known rule in logic, the cause of the cause, is the cause of that which is caused thereby.