9 Say the welcoming word to God - "Jesus is my Master" - embracing, body and soul, God's work of doing in us what he did in raising Jesus from the dead. That's it. You're not "doing" anything; you're simply calling out to God, trusting him to do it for you. That's salvation.
Matthew Henry's Commentary on Romans 10:9
Commentary on Romans 10:5-11
(Read Romans 10:5-11)
The self-condemned sinner need not perplex himself how this righteousness may be found. When we speak of looking upon Christ, and receiving, and feeding upon him, it is not Christ in heaven, nor Christ in the deep, that we mean; but Christ in the promise, Christ offered in the word. Justification by faith in Christ is a plain doctrine. It is brought before the mind and heart of every one, thus leaving him without excuse for unbelief. If a man confessed faith in Jesus, as the Lord and Saviour of lost sinners, and really believed in his heart that God had raised him from the dead, thus showing that he had accepted the atonement, he should be saved by the righteousness of Christ, imputed to him through faith. But no faith is justifying which is not powerful in sanctifying the heart, and regulating all its affections by the love of Christ. We must devote and give up to God our souls and our bodies: our souls in believing with the heart, and our bodies in confessing with the mouth. The believer shall never have cause to repent his confident trust in the Lord Jesus. Of such faith no sinner shall be ashamed before God; and he ought to glory in it before men.