'Faithfully' in the Bible

And he charged them, saying, Thus shall ye do in the fear of the LORD, faithfully, and with a perfect heart.

And brought in the offerings and the tithes and the dedicated things faithfully: over which Cononiah the Levite was ruler, and Shimei his brother was the next.

And the men did the work faithfully: and the overseers of them were Jahath and Obadiah, the Levites, of the sons of Merari; and Zechariah and Meshullam, of the sons of the Kohathites, to set it forward; and other of the Levites, all that could skill of instruments of musick.