Can we assume that the God of Israel is different from the God of today?
No, one cannot assume that the God of Israel is different from the God of today. The text explicitly states you cannot take for granted that the God of Israel is any different than the God of today. Therefore, the God of Israel and the God of today are not different; no distinction should be assumed.
Les explains that you cannot take for granted that the God of Israel is any different than the God of today. He then points to Deuteronomy 27:15, where God says cursed is the man who makes any graven or molten image, an abomination to the Lord, the work of the craftsman, and puts it in a secret place; all the people agree, saying Amen. In Deuteronomy 28, God uses the conditional word 'if,' leaving it up to the nation of Israel and their free will, not making them robots. The setting is Israel ready to occupy Canaan under Joshua, and Moses writes his own obituary by inspiration. These passages show God's consistent character and dealings with Israel.