If a person believes in his/her heart but has not confessed Jesus as Lord with his mouth, can he or she be saved?
The passage you are referring to is found in Romans 10:8-9,
But what does it say? “THE WORD IS NEAR YOU, IN YOUR MOUTH AND IN YOUR HEART” – that is, the word of faith which we are preaching, that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you shall be saved. (NASB) Romans 10:8-9
Some have said this passage means we must confess with our mouth to be saved but that is not what this passage is saying. There have been many who have stood up in front of some group, church or some convention and said Jesus was their Savior who years later admit they are not Christians.
The passage is talking about what is in our heart and in our mind. The Greek word for “confess” is HOMOLEGO. It means “to say the same thing” or to admit with our mouth. The idea is that our mouth is saying what is in our heart.
Romans is not the only place scripture talks about confession with our mouth. Listen to these passages about confessing with our mouth,
And I say to you, everyone who confesses Me before men, the Son of Man shall confess him also before the angels of God. (NASB) Luke 12:8
Fight the good fight of faith; take hold of the eternal life to which you were called, and you made the good confession in the presence of many witnesses. (NASB) 1 Timothy 6:12
Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. (NASB) 1 John 4:15
Each of these passages simply says that real, true Christians who believe Jesus is the Son of God and consider Him to be their Lord will not deny Him. A Christian’s words will reveal what he or she believes in his/her heart. Yes, some Christians are cowards, and others have no fear. We need to pray and ask the Holy Spirit to give us boldness to confess with our mouth.
No, our salvation does not depend on what we say. The issue is what do you believe? If you believe in your heart that Jesus is Lord, you are saved. You could be a Christian like Joseph of Arimathea (John 19:38) who apparently did not tell very many that he was a Christian because the Holy Spirit describes him as a “secret” Christian.
The real question we need to ask ourselves is, “Does my mouth reveal what I really and honestly believe in my heart about Jesus – that He is Lord of life?” That is the meaning of the passage (read 1 Corinthians 12:3). And we should be telling others about Jesus. God wants us to be bold. So pray for boldness to speak out like the early Christians did in Acts 4:29-31.