This passage describes the condition of a unregenerate heart–it does it’s own thing. Here Moses is devising a method by which the Hebrews could be reminded of the commandments of God. Throughout the Bible there is a strong and continuing demand that we know and do what God commands.
At that time few of the Hebrews were literate. So, the fringe on the garments were to be a devise to help the citizens remember what God demanded of them. Further, they were about to journey into an area where the natives did not know the commandments of God. They would not be living by these commandments. Apparently, elements of their culture would be found to be attractive to the Hebrews.
We are literate. But we live in a world that still does not follow the teachings of God. We are constantly tempted. We are constantly given opportunities to rebel, coast along, simply ignore what God demands of us. Do we not also need some help in complying with the teachings and demands of God? Probably?
It seems to me that there is a broad “disconnect” between the teachings of God and the life of many church members. This is very disappointing. While salvation is not achieved by doing good works, good works and obedience to God should be the product of salvation.