God instructed Moses in the ordination of Aaron and his sons to serve him as priests in Exodus 29. But in Exodus 28 he instructed Moses in dressing them for the occasion. In that scene they had clothes that were fit for their holy calling. In the NT and today we have been fitted with clothes appropriate for our holy Christian calling as a priesthood. Those "clothes" are love, humility, the new self, the armor of God, etc. Dress for the occasion.