What is the word of faith? We have the tenor of it, v.9, 10. What is promised to us? Thou shalt be saved. It is salvation that the gospel exhibits and tenders which Christ is the author of, a Savior to the uttermost.
Upon what terms? Two things are required as conditions of salvation:
(1) Confessing the Lord Jesus-openly professing relation to Him and dependence on Him, standing by Him in all weathers. Our Lord Jesus lays a great stress upon this confessing Him before men; see Matthew 10:32, 33.
(2) Believing in the heart that God raised Him from the dead. The profession of faith with the mouth, if there is not a power of it in the heart, is but a mockery; especially concerning His resurrection, which is the fundamental article of the Christian faith.
This is further illustrated, v. 10, and the order inverted, because there must first be faith in the heart before there can be an acceptable confession with the mouth. It is with the heart that man believeth, which implies more than an assent of understanding, and takes in the consent of the will. This is unto righteousness. There is the righteousness of justification and the righteousness of sanctification. Faith is to both.
It is with the mouth that confession is made-confession to God in prayer and praise, confession to men by owning the ways of God before others. And this is said to be unto salvation, because it is the performance of the condition of that promise. So that we must have here a brief summary of the terms of salvation, that we must give up, to god, our souls and bodies-our souls in believing with the heart, and our bodies in confessing with the mouth.”
-Matthew Henry from A Closer Walk With God Daily Readings From Matthew Henry by Marshall Pickering Daybreak Books Grand Rapids, MI 1987 Page 225