'Faithless' in the Bible

For the Lord humbled Judah because of Ahaz king of Israel, for Ahaz had allowed unrestrained and undisciplined behavior in Judah and had been very unfaithful to the Lord.

Moreover, we have prepared and consecrated all the utensils which King Ahaz had discarded during his reign in his unfaithfulness; and behold, they are in front of the altar of the Lord.”