he is addressing unbelievers in verses 5-13, which is why Paul uses THEY in v14.
if Paul was addressing unbelievers he would have used the word "you" and not "they."
Here is how Paul addresses believers:
"Or do you not know, brethren (for I speak to those who know the law), that the law has dominion over a man as long as he lives?" (Ro.7:1).
"For you did not receive the spirit of bondage again to fear, but you received the Spirit of adoption by whom we cry out, “Abba, Father" (Ro.8:15).
The word "address" means
"to speak or write directly to" (
Merriam-Webster Collegiate Dictionary).
Here Paul is not writing directly to these unbelievers:
"How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?" (Ro.10:14).
Paul is not writing directly to them so he is not addressing them. If he was writing directly to these unbelievers this is the way that he would do it:
"How then shall you call on him in whom you have not believed? and how shall you believe in him of whom you have not heard? and how shall you hear without a preacher?"
If Paul was addressing unbelievers that is what he would have written. But since that is not what He wrote then he was not writing to them directly.
Therefore, Paul was not addressing the unbelievers in chapter 10.
And if Paul was addressing unbelievers in the first part of chapter 10 then why would he all of a sudden stop addressing them and start refrrring to them as "they"?
And if Paul was addressing unbelievers at Romans 10 then why would he not include them where he says exactly whom his epistele was addressed to:
"To all that be in Rome, beloved of God, called saints: Grace to you and peace from God our Father, and the Lord Jesus Christ" (Ro.1:7).
If his epistles were addressed to unbelievers also, why didn't he mention that?