'Faithful' in the Bible

How is the faithful city become an harlot! it was full of judgment; righteousness lodged in it; but now murderers.

And I will restore thy judges as at the first, and thy counsellers as at the beginning: afterward thou shalt be called, The city of righteousness, the faithful city.

And I took unto me faithful witnesses to record, Uriah the priest, and Zechariah the son of Jeberechiah.

Thus saith the LORD, the Redeemer of Israel, and his Holy One, to him whom man despiseth, to him whom the nation abhorreth, to a servant of rulers, Kings shall see and arise, princes also shall worship, because of the LORD that is faithful, and the Holy One of Israel, and he shall choose thee.