'Faithless' in the Bible

And Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I bear with you? bring him hither to me.

And he answereth them and saith, O faithless generation, how long shall I be with you? how long shall I bear with you? bring him unto me.

And Jesus answered and said, O faithless and perverse generation, how long shall I be with you, and bear with you? bring hither thy son.

Then saith he to Thomas, Reach hither thy finger, and see my hands; and reach hither thy hand, and put it into my side: and be not faithless, but believing.

if we are faithless, he abideth faithful; for he cannot deny himself.