'Faithful' in the Bible

If any be blameless, the husband of one wife, having faithful children not accused of riot or unruly.

Holding fast the faithful word as he hath been taught, that he may be able by sound doctrine both to exhort and to convince the gainsayers.

This is a faithful saying, and these things I will that thou affirm constantly, that they which have believed in God might be careful to maintain good works. These things are good and profitable unto men.