Jamieson, Fausset and Brown on Joshua 24:14-28

14-28. Now therefore fear the Lord, and serve him in sincerity and in truth--After having enumerated so many grounds for national gratitude, Joshua calls on them to declare, in a public and solemn manner, whether they will be faithful and obedient to the God of Israel. He avowed this to be his own unalterable resolution, and urged them, if they were sincere in making a similar avowal, "to put away the strange gods that were among them"--a requirement which seems to imply that some were suspected of a strong hankering for, or concealed practice of, the idolatry, whether in the form of Zabaism, the fire-worship of their Chaldean ancestors, or the grosser superstitions of the Canaanites.