The ring is not for God. It is for the stranger on the street to see so that it can be proclaimed that you belong to someone else. It really is a proclaimation. A sign ... so to speak. And some will say that it is how you act rather than a sign. While your actions are important ... they are not enough for most in this world unfortunately. To not wear a ring is known as dishonesty in many cultures. Now that is a witness that we don't want to display.
... Unless you're straightforward. That should be more than enough for anyone. People treat a ring as a joke too these days. It does not at all prevent another person from whatever they may think or say.
As for cultures, I put that second place IF that to principles I've found in the Bible. Some will wear it, some will not.. I've already stressed much of my points I think lol.
What's the importance of a wedding ring, and yet we see sky rocketing adultery and divorce! No need, sometimes I have this strong feeling it's because we have brought demons into the church by coping the world, that's the reason whey the line of demarcation between the church and the world is razor thin.
Satan has a right to claim all kinds of jewelry and wedding rings. God's people should put these things away.