'Faithful' in the Bible

He guards the steps of his faithful ones, while the wicked are made silent in darkness. He grants the request of the one who prays. He blesses the year of the righteous. Indeed it's not by strength that a person prevails.

And I'll raise up for myself a faithful priest who will do according to what is in my heart and according to my desire. I'll build for him an enduring house and he will walk before my anointed one forever.

Ahimelech answered the king, "Who among all your officials is as faithful as David? He is the king's son-in-law, the captain of your bodyguard, and he's honored in your household.