'Faithful' in the Bible

Wherefore it behoved him in all things to be made like to his brethren, that he might be a merciful and faithful high priest in things relating to God, to make propitiation for the sins of the people;

who is faithful to him that has constituted him, as Moses also in all his house.

And Moses indeed was faithful in all his house, as a ministering servant, for a testimony of the things to be spoken after;

Let us hold fast the confession of the hope unwavering, (for he is faithful who has promised;)

By faith also Sarah herself received strength for the conception of seed, and that beyond a seasonable age; since she counted him faithful who promised.