'Believe' in the Bible

What then? If some did not believe, does their unbelief nullify the faithfulness of God?

namely, the righteousness of God through the faithfulness of Jesus Christ for all who believe. For there is no distinction,

And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised, so that he would become the father of all those who believe but have never been circumcised, that they too could have righteousness credited to them.

but also for our sake, to whom it will be credited, those who believe in the one who raised Jesus our Lord from the dead.

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

because if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.

How are they to call on one they have not believed in? And how are they to believe in one they have not heard of? And how are they to hear without someone preaching to them?

Now may the God of hope fill you with all joy and peace as you believe in him, so that you may abound in hope by the power of the Holy Spirit.