Romans 10:9 "That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. 10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. 11 For the scripture saith, Whosoever believeth on him shall not be ashamed. 13 For whosoever shall call upon the name of the Lord shall be saved."Other places scripture says by faith you are saved (Ephesians 2:8). Here in Romans it says two things: (1) confess Jesus with the mouth, and (2) believe that He is raised from the dead. Hence, faith is trusting that Jesus was resurrected, and if that is believed, those who have the hope of salvation tell others about Him. The first condition is faith, and the second a testimony of that faith. It is important to testify of one's faith in Jesus. Why?
Romans 10:11 "For the scripture saith, Whosoever believeth on him shall not be ashamed."It would seem that some were ashamed that they had faith; to wit: ashamed that Jesus still lives after dying on the cross. Paul taught that the resurrection of Jesus was important for faith to exist because if Jesus doesn't live, how can one believe that they will have eternal life. Inevitably, Jesus is all about you. Because He lives today, you can live tomorrow, as Christians sing.
Acts 24:15 "And have hope toward God, which they themselves also allow, that there shall be a resurrection of the dead, both of the just and unjust."You best believe in the resurrection, both for those who are saved, but the unsaved as well. The reader may find that unusual, but even the unpardoned sinner will be resurrected. Their bodies will arise from the dust, their soul will return from hell, and they will stand before God to hear their crimes and penalty. All will be at the Great White Throne judgment, but only those who were not reprieved by Jesus, will be judged guilty as charged.
For the part about confessing with the tongue; that is imperative. It's testifying of belief, and confessing is the demonstration of faith. It is something Christians DO to acknowledge, and is imperative to be saved. By grace you are saved, and it is not of yourselves (Ephesians 2:8), but if you get the gift of grace, if there is gratitude, you tell others about it. That's like winning $25,000,000 at the lottery, and the enthusiasm that comes about by winning the prize. Likewise, if one wins the prize of eternal life, there must be enthusiasm there to tell others about your winnings!
A lack of enthusiasm may indicate doubt which is opposite of faith. With faith, there will be enthusiasm, or it is no faith at all!
When I was born-again as a teenager, I kept quiet about it. I was a secret Christian. Indeed, that cannot be. Peter tried that when he denied Jesus thrice. Those who heard him deny Jesus knew that he was either a liar or ashamed. Scripture implies that he was ashamed. Of course he later confessed, so he was saved, but Christians must never be ashamed. Now I confess with my mouth, and keyboard, that I believe in the resurrection and am not ashamed of the one who died for me!
Sometimes when people sin, thy conceal their belief in Christ. That is being ashamed of two things: (1) the sin, and (2) of Jesus. It's keeping faith a secret so that the sin is not pinned on you. That doesn't work. Rather than a secret Christian who sins, Christians who sin, must confess Jesus. As a Christian who sometimes sins, I don't deny Jesus, but know that by grace I am saved. I am not ashamed of Him, but me!
When I was young, the preacher always asked for a testimony either after "praying through" as it was called, or before baptism or both. Nowadays, preachers often forget that essential part - standing there in humility confessing Jesus with enthusiasm. It is important so as to not be ashamed.