The apostle Paul began to proceed to the spiritual battle with the Christian church of Jewish origin in Rome. He explained to them that preaching has steps and various elements. True faith begins with the heart, for man believes in his heart. This faith means that the believer is entirely and closely united and connected to him in whom he believes.In addition to faith, there must be a spoken testimony, for the truth must cast away darkness. Faith and testimony are connected together. The testimony speaks of the faith so that, on the one hand, the hearers may understand and, on the other hand, that the witness himself may gain more certainty of his own faith.The guaranty of faith, which Paul himself and other witnesses of Christ presented, has some principles and doctrines:1. Jesus is the Lord. He owns the universe, and all authority has been given to him. David testified clearly: The LORD says to my Lord: "Sit at my right hand until I make your enemies a footstool for your feet" (Psalm 110:1). The apostle John described in detail the Lamb of God seated on the throne (Revelation 5:1-14); and Paul testified in his glorification of the crucified who rose from the dead, that at the name of Jesus every knee should bow, of those in heaven, and of those on earth, and of those under the earth, and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father (Philippians 2:5-11).The short statement “Jesus is Lord” is the backbone of the Christian faith. It means that Jesus Christ is a true God in the unity of the Holy Trinity. He lives and reigns in full harmony with his heavenly Father.2. This glorification of Christ is founded on the fact that the holy God raised him, who was crucified and dead, from death to life. The resurrection of Christ is the second pillar of the Christian faith; for if the Son of Man was not truly raised, his body is completely decayed. But he rose from his grave, and walked through rocks and walls with his spiritual body. Jesus is living, whereas all the founders of other religions are dead with decayed bodies. The resurrection of Christ is a proof of his holiness, his victory, his power, and his complete salvation.3. Whoever believes these facts in his heart, and testifies what he is well assured of, is saved. This assurance leads the believer to testify boldly and joyfully that Jesus is the Victor. In his testimony he partakes of the life, Spirit, and peace of Christ. He who is founded on Christ, and relies on him, will never fail.4. On this growing assurance, Paul says that he who believes in the Lord Jesus Christ is justified by the holy God, freed from all his sins, acquitted in the last judgment, and admitted as a member into the spiritual family of God, grafted into the spiritual body of Christ. In short, the believer connects himself firmly and forever with Jesus. Complete salvation and justification are attained through the testimony of his faith, that he is a justified sinner acceptable to God. The testimony is not a reason for salvation, for the essential justification is only attained by faith. Rather, the testimony realizes and deepens such justification bestowed on the believer in order that his salvation may practically and tangibly become mature. Justification and salvation are derived from Christ, and are attained through the testimony of the believer to his saving Lord. 5. After this indication of faith in the New Testament, and justification attained only by grace, Paul aims a blow: there is no difference between a Jew and a Christian if both believe in Christ and have been renewed by his grace. There is only one Lord, one Savior, and one Redeemer for them both. The Jews are not saved by Abraham or Moses, but by Jesus alone. The salvation of Christ, his power, life, and love pertain to both Jews and Christians in the same manner. There is no other crucified one who has given himself as atonement for everybody, other than the gentle Lamb of God who took away the sin of the world.6. Paul expresses clearly that Jesus is rich, and he makes all those who ask of him partners in his spiritual riches (Romans 10:12-13). He gives his Holy Spirit, his divine power, and his eternal love to everyone who prays to him, pouring out his heart before the living Jesus Christ in person, without resorting to the saints, or to the virgin Mary. Without your supplication for salvation, sanctification, and redemption, nothing happens to you. Grace is available to all, but we must seek it (Joel 3:5). Through supplication, we hear the voice of the Holy Spirit in us crying out: “Abba, Father” (Romans 8:15-16).