Why We Dress Up for Church

Not long ago there was a billboard for a non-Catholic church on the main Street in our town. The billboard proudly proclaimed, "These are my Sunday Clothes" and pictured a man in jeans, a t-shirt and a leather coat. I remember wondering why is it that it is such a draw to show up for church so casually.
Not long after I was having a conversation with some friends, who as it happens are also not Catholic. The topic of Sunday dress had come up and they also proudly proclaimed that they show up dressed just as they were that weekend. Shorts, tshirt, jeans, whatever they were wearing for the rest of the day. Their reason for this being acceptable was they were pretty sure that "Jesus didn't care how they dressed"
Even in our Catholic churches you do not have to look far to find this casual attitude toward attire. It is a popular position to take Jesus as our best friend, who takes us as we are. My friends that weekend did not care what I was wearing, I didn't care what they were wearing, so why does Jesus care what I decide to wear to church?
The answer could be, He just might not actually care, but I think the more appropriate question is why don't we care? Jesus does want us, sinner and all. Jesus will take us as we are. He wants us to come to Him regardless of what we are wearing I am sure. It should however maybe occur to us to ask ourselves what Jesus gave so that He could take us as we are. During this time of lent we are reminded more than ever of the sacrifice that He made for us. As Catholics we witness that sacrifice every Sunday and stand in His true presence. He died a horrible death after being tortured for my sins, for everyone's. He died because he knew I was not good enough, He died so He could take me as I am.
When I go to a funeral, even for someone I don't know well, I dress up. I wear my Sunday best. I also notice at a funeral 98% of people do the same. We dress up out of respect for the life of the person that has just died. We dress up to say, "your life meant something to me." We are capable of showing respect through our dress for strangers. We dress up for work, we dress up for a night out, we dress up for a funeral. Why should Jesus deserve any less from me? He has given me the chance of eternal life. How can I show up in jeans or shorts an say, "hey bud, must have sucked being up on that cross."
Dressing up for church also demonstrates to my family, and the rest of the world that we are going to Church on Sunday. That is our destination. We are not stopping at church on the way to a bbq. We are not going to the football game but have to make an appearance at church first. We are going to Church. We are going to show our reverence for the sacredness that is the Mass. Dressing up is an outward sign that we can give to show our respect and gratitude for Christ on the cross.
When we show up for church dressed casually there is a tendency to have a casualness toward the Mass. When we show up casually we remove the sacred from the Mass. When we remove the sacred from the Mass, we ignore the sacrifice. The Mass then becomes for us at best a symbolic meal rather than a sacred act.
I have been to many churches, traditional churches, where the priests preach continuously on the importance of dress and modesty in our display of reverence toward the Lord. I am always grateful when I am asked outright if I feel I am giving Christ all the devotion He deserves. Even outside of Church, our kids recently were sent home a letter addressing proper dress for band students at a concert. The letter explicitly listed appropriate dress for men and women to wear for the concert and also explicitly listed, that leggings are not pants for women and will not be allowed.
If we are required to wear pants for something as simple as a band concert shouldn't we asked to do the same for Mass?
That is why we dress up for Church, that is why my wife and I ask our kids to dress up for Church. The Mass should stand apart from our daily routine. We should prepare ourselves to have to go there. The act of dressing up for Mass, as well as the act of changing into more casual clothes after Mass, very clearly marks for me and my family that we have just been somewhere important. That we have just been to see Someone important. Christ deserve something more from me than I give the rest of the world. His sacrifice deserves my outward appreciation and dressing up for Mass is one way I can display that respect to my family.