'Believer' in the Bible

Now Paul traveled to Derbe and also to Lystra. A disciple named Timothy was there, the son of a Jewish woman who was a believer [in Christ], however, his father was a Greek.

As for the one whose faith is weak, accept him [into your fellowship], but not for [the purpose of] quarreling over his opinions.

What harmony can there be between Christ and Belial (Satan)? Or what does a believer have in common with an unbeliever?

Remember me to every saint in Christ Jesus. The brothers who are with me greet you.

Now we command you, believers, in the name of our Lord Jesus Christ and by His authority, that you withdraw and keep away from every brother or sister who leads an undisciplined life and does not live in accordance with the tradition and teaching that you have received from us.

no longer as a slave, but [as someone] more than a slave, as a brother [in Christ], especially dear to me, but how much more to you, both in the flesh [as a servant] and in the Lord [as a fellow believer].

The one who loves and unselfishly seeks the best for his [believing] brother lives in the Light, and in him there is no occasion for stumbling or offense [he does not hurt the cause of Christ or lead others to sin].

By this the children of God and the children of the devil are clearly identified: anyone who does not practice righteousness [who does not seek God’s will in thought, action, and purpose] is not of God, nor is the one who does not [unselfishly] love his [believing] brother.

But whoever has the world’s goods (adequate resources), and sees his brother in need, but has no compassion for him, how does the love of God live in him?

And this commandment we have from Him, that the one who loves God should also [unselfishly] love his brother and seek the best for him.

If anyone sees his brother committing a sin that does not lead to death, he will pray and ask [on the believer’s behalf] and God will for him give life to those whose sin is not leading to death. There is a sin that leads to death; I do not say that one should pray for this [kind of sin].