“ Now therefore, fear YHWH, and serve him in sincerity and in truth, and put away the gods which your fathers served beyond the River and in Egypt, and you serve YHWH.”
The requirements were simple and yet demanding. They were firstly that they should ‘fear YHWH', recognise His greatness, His sovereignty and His power, and serve Him without pretence, but truly and honestly. This meant, of course, in accordance with the Law already given to them.
And secondly that they should reject all rivals. It has already been mentioned that their fathers had worshipped other gods beyond the River, and now is added the fact of gods they had worshipped in Egypt. These were probably not the native gods of Egypt, for there is never any hint that they worshipped them, but gods commonly worshipped in Egypt by sojourners (also taken up by many Egyptians), on which for example had possibly been based the golden calves and the teraphim so often mentioned. We must remember that a good proportion of ‘the children of Israel' were from a mixture of nations and would have worshipped a number of gods (Exodus 12:38), and it is clear that traces of that worship were still among them (compare Genesis 35:2).
So Joshua was now calling on them to renounce these ‘gods' and serve YHWH only. Syncretism was always a huge danger, but it is noteworthy that at this stage there is no suggestion of their pandering to Canaanite gods, although Joshua was aware of the danger (Joshua 24:15). They had not yet begun to mix with the Canaanites and learn their ways, a remarkable indication of the authenticity of the speech (a later writer would not have been able to resist incorporating such an idea here).