Acceptance of God's gift of salvation has two aspects. The first is an inner aspect, that comes from the heart. This inner aspect involves believing from the heart that Jesus is Lord, that He died for us, and that God raised Him from the dead. The second aspect is an outer aspect that comes from the mouth. The belief that comes from the heart must make its way to the mouth. The mouth must profess the belief and declare that Jesus is Lord (Romans 10:9).
A person who believes with his heart is justified by God. The word justified means acquitted or declared innocent. When a person believes with his heart that Jesus is Lord, that He died for our sins, and was raised from the dead, God declares that person to be righteous. Basically, it is as if the person had never sinned. And, when that person professes his faith with his mouth, confessing and repenting of his sins, he is saved, set free from the bondage and the penalty of his sin (Romans 10:10).
Salvation is a gift to be shared. It is God's desire that all people shall be saved. Romans 10:13 says that everyone who calls upon the name of the Lord Jesus will be saved. But how can people call upon the name of someone that they have never heard of, let alone believed in (Romans 10:14)? Someone must tell them about Jesus. Someone who has believed in Jesus with his heart and declared his faith with his mouth. And that person needs to be sent by God to tell others the good news of Jesus (Romans 10:15).
Who is the person sent by God to share the good news? A preacher, an evangelist, a pastor? The answer to this question is simple. The person sent to spread the good news is me, it is you, it is all those who have received God's gracious gift of salvation as a result of their faith in Jesus and their acceptance of Him as Lord and Savior of their lives. The Bible says, in Psalm 107:2, "Let the redeemed of the Lord say so." All of us who have been redeemed, who have been saved, should be willing to tell others about the good news of salvation through Jesus. In fact, Jesus has called all believers to be His witnesses throughout the world (Acts 1:8).
Believe in the Lord with your heart and declare your faith with the words of your mouth, not only for your own benefit, but for the benefit of all.