'Believe' in the Bible

What then? If some did not believe, will their unbelief cancel God’s faithfulness?

—that is, God’s righteousness through faith in Jesus Christ, to all who believe, since there is no distinction.

And he received the sign of circumcision as a seal of the righteousness that he had by faith while still uncircumcised. This was to make him the father of all who believe but are not circumcised, so that righteousness may be credited to them also.

but also for us. It will be credited to us who believe in Him who raised Jesus our Lord from the dead.

Now if we died with Christ, we believe that we will also live with Him,

If you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised Him from the dead, you will be saved.

But how can they call on Him they have not believed in? And how can they believe without hearing about Him? And how can they hear without a preacher?