Verses with the word infidel in the New Testament (2 verses):

2 Corinthians 6:15
And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?

1 Timothy 5:8
But 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.