Benjamin,
You make much of the "you" found in Romans 10, but again your proof - text fashion has lead you to askew the meaning of the passage.
Here is Romans 10 (which includes your verse):
5 For Moses writes that the man who practices the righteousness which is based on law shall live by that righteousness. 6 But the righteousness based on faith speaks as follows: “Do not say in your heart, ‘Who will ascend into heaven?’ (that is, to bring Christ down), 7 or ‘Who will descend into the abyss?’ (that is, to bring Christ up from the dead).” 8 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, 9 that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; 10 for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation. 11 For the Scripture says, “Whoever believes in Him will not be disappointed.” 12 For there is no distinction between Jew and Greek; for the same Lord is Lord of all, abounding in riches for all who call on Him; 13 for “Whoever will call on the name of the Lord will be saved.”
14 How then will they call on Him in whom they have not believed? How will they believe in Him whom they have not heard? And how will they hear without a preacher? 15 How will they preach unless they are sent? Just as it is written, “How beautiful are the feet of those who bring good news of good things!”
16 However, they did not all heed the good news; for Isaiah says, “Lord, who has believed our report?” 17 So faith comes from hearing, and hearing by the word of Christ.
Now I won't go into a verse by verse explanation, this post would be far too long.
Look at the word HEART. Does not the Scripture state that what is in the heart WILL come out of the mouth?
So, when a believer responds to salvation and in that process some refer to as "born again" they, just as a new born, cannot help but cry out.
But what must come before all that?
The gospel. For it is the Word of God (Christ is the Word) that penetrates the heathen, implanting the seed in the fertile soil made ready by God's timing and the human is saved - not because they said a certain prayer or repeated a certain mantra.
The believer is saved because the Word finding good earth WILL grow to harvest. Other soil does not respond to harvest.
It is also important to notice that Paul is NOT talking to the heathen lost souls, but he is visiting this part of the letter upon BELIEVERS. He is showing by pointing out from their own experience that because they are saved as evidenced by the heart and the response of the conversation (mouth), that now there is a need of witnessing and evangelizing. He is presenting a quest to them (as evidenced starting in verse 14 and following.
He is also warning them not to be discouraged for even though the Scriptures are given, no ALL will respond, because just as the parable of the soil, not all dirt is prepared by God to receive the seed (Word) the same way. Some don't even have any dirt at all.
But, at least you tried, which really is an improvement!