Infidel

Concise Bible Dictionary:

The Greek word is ἄπιστος, “not believing,” and hence an “unbeliever” (2 Cor. 6:1515And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? (2 Corinthians 6:15); 1 Tim. 5:88But if any provide not for his own, and specially for those of his own house, he hath denied the faith, and is worse than an infidel. (1 Timothy 5:8)). The word is translated “unbeliever” (Luke 12:4646The lord of that servant will come in a day when he looketh not for him, and at an hour when he is not aware, and will cut him in sunder, and will appoint him his portion with the unbelievers. (Luke 12:46); 1 Cor. 6:66But brother goeth to law with brother, and that before the unbelievers. (1 Corinthians 6:6); 1 Cor. 14:2323If therefore the whole church be come together into one place, and all speak with tongues, and there come in those that are unlearned, or unbelievers, will they not say that ye are mad? (1 Corinthians 14:23); 2 Cor. 6:1414Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? (2 Corinthians 6:14)); and “unbelieving” (1 Cor. 7:14-1514For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy. 15But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace. (1 Corinthians 7:14‑15); Titus 1:1515Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled. (Titus 1:15); Rev. 21:88But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death. (Revelation 21:8)). Thus the scriptural use of the term does not imply the denial of the truth of Christianity, as it is now commonly understood.