Thank you for your inquiry and I look forward to having you worshipping with us on this occasion.
In our present day and age, it seems that more often than not we live in a very casual type of society; where an atmosphere of “casual dress” and “business casual” are the cultural norm. This prevailing attitude has somewhat permeated even into the life of many churches (one often hears rumors of people in other Christian denominations walking up to the chalice in cut-off jeans, Kiss t-shirts, and tennis shoes). Such an attitude is at odds with our “ethos” or way of thinking/acting.
In the Orthodox Church we try to maintain and hold to the high-calling and expectations of our worship services. Therefore, although one needs not necessarily wear an expensive three-piece suit or formal designer dress, we still expect people to dress appropriately and with the reality that we come to stand and worship in the presence of God. And although God might not care what we wear to church (He did, after all, create us to live naked and without shame), we, ourselves, still should.
Therefore, most men who attend our services generally wear suits or sport coats, and the woman wear dresses (or in some instances, nice pants suits).
A good rule of thumb, however, is to simply “dress your best” without putting on airs or calling attention to yourself. Yet if one is poor and does not own anything better, than come in the cleanest, neatest clothing possible.
Keep in mind that “dressing-up,” especially given our society’s current standards, in effect becomes an offering (sacrifice) of respect to God.