We are now under grace and no longer have priest, but the priesthood of the believer. I believe the way we dress when we worship, especially when we lead in worship reflects our understanding of the awesome holiness of God. While I do not have a designated dress code for appearing before God, don't you think that our dress, our conduct reflects on His person?
Our President very seldom appears in public in casual attire; the Presidential Candidates always appear in suits when debating and business dresses; CEOs for the majority appear in suits; News casters, car salesmen, lawyers wear their best. Yet it seems that we Christians have become so informal, so casual in our approach to a Holy God that we dress like we are going to the gym or the beach or to work on our cars.
I know that some will find fault, will wonder if I am talking about them and will reject all thoughts of dressing up for the Lord God Almighty. As for me I will wear my best and show my respect and fear of a Holy God who wrote 3 chapters and more about how a Priest should appear before the Lord. Under grace I will do more than under the Law.