'Believe' in the Bible

What then? If some did not believe or were unfaithful [to God], their lack of belief will not nullify and make invalid the faithfulness of God and His word, will it?

This righteousness of God comes through faith in Jesus Christ for all those [Jew or Gentile] who believe [and trust in Him and acknowledge Him as God’s Son]. There is no distinction,

He received the sign of circumcision, a seal or confirmation of the righteousness which he had by faith while [he was still] uncircumcised—this was so that he would be the [spiritual] father of all who believe without being circumcised—so that righteousness would be credited to them,

but for our sake also—to whom righteousness will be credited, as those who believe in Him who raised Jesus our Lord from the dead—

Now if we have died with Christ, we believe that we will also live [together] with Him,

because if you acknowledge and confess with your mouth that Jesus is Lord [recognizing His power, authority, and majesty as God], and believe in your heart that God raised Him from the dead, you will be saved.

But how will people call on Him in whom they have not believed? And how will they believe in Him of whom they have not heard? And how will they hear without a preacher (messenger)?

That is true. They were broken off because of their unbelief, but you stand by your faith [as believers understanding the truth of Christ’s deity]. Do not be conceited, but [rather stand in great awe of God and] fear [Him];

One man’s faith permits him to eat everything, while the weak believer eats only vegetables [to avoid eating ritually unclean meat or something previously considered unclean].