Cope, chasuble dalmatic, tunicle, stole, maniple, amice, tippet, cincture, alb, cassock, surplice, clerical collar, mitre, and biretta–and those are just the pieces that I could think of off the top of my head. And just as there is a plethora of liturgical vestments which a pastor might wear in a given situation, there is an even greater range of styles and designs for each piece. The possibilities are seemingly limitless.
But why? Why do we have all of this? Why are there so many pieces? What's the point?
Vestments are nothing new to the Church. They have existed at least since Exodus 39.
"From the blue and purple and scarlet yarns they made finely woven garments, for ministering in the Holy Place. They made the holy garments for Aaron, as the LORD had commanded Moses…They also made the coats, woven of fine linen, for Aaron and his sons, and the turban of fine linen, and the caps of fine linen, and the linen undergarments of fine twined linen, and the sash of fine twined linen and of blue and purple and scarlet yarns, embroidered with needlework, as the LORD had commanded Moses" (Exodus 39:1, 27-29 ESV).
Imagine that. The Lord prescribed the following vestments to be worn by the priests serving in His tabernacle: coats (like a chasuble), turbans and caps (like a mitre or biretta), linen undergarments (like an alb or a cassock and surplice), and sashes (like a stole), all of which are to be embroidered (like adorning them with symbols).
When the priest entered into the tabernacle, into the Holy Place, and into the Holy of Holies, he was clothed according to specific instructions from the Lord. That is, the man was covered in garments that had been specifically appointed for use in the Lord's house and in the Lord's service. They covered the man, drawing attention away from him; they indicated to others that he was doing something holy; and they taught the people through symbols and imagery. (The section in Exodus 39 about the breastplate contains quite a bit of this type of detail.)
And that's the basic purpose of it all: to cover the man and set him apart for a holy purpose.
The Lord works through means. Apart from the means of His Son Jesus Christ, all of those means are tainted by sin: bread and wine, water, husbands and fathers, wives and mothers, and men placed into the Office of the Holy Ministry.
And so as a way of turning attention away from the sinful man standing in the stead and by the command of Christ and as a way of pointing toward the holiness of what he is doing in Christ's place, the man covers himself. He wears sacred garments that obscure himself and indicate that he is doing some sacred.
To be sure, these garments are not to be for show. They are also to be for promoting piety and reverence both in the man wearing them and in the people seeing them. Now, that doesn't mean that they cannot be beautiful. I can only imagine how wonderful that breastplate must have looked! But anytime that they are designed and worn for the sake of adoring the man wearing them and not the Man whose office is being filled, then they have crossed the line from the sacred into the profane. Anytime that they are intended to promote an organization or an agenda other than the Church of Christ, the preaching and teaching of the Gospel, and the right administration of the sacraments, they are no longer serving their intended purpose, but seek to introduce non-Christological themes into Christ's service. If you have not seen it before, there is a website that reveals quite a number of these horrendous abominations to sacred space.
(Incidentally, it is okay for pastors to post pictures of themselves wearing their vestments, just the same as it is okay to post pictures of liturgical art, videos of choirs singing, or texts of sermons.)
To be sure, I am not contending that vestments are commanded for our usage in the Word of God.
I am contending, however, that vestments are commended for our usage in the Word of God, just as they are in the Lutheran Confessions. Article XXIV of the Apology even says to us, "And the usual public ceremonies are observed, the series of lessons, of prayers, vestments, and other like things." They are good, salutary tools to use. They cover the man while teaching about the faith. The colors, the symbols, the designs, even the vestments themselves proclaim something about what is going on in the service that day. Vestments serve to distinguish between the common, unholy things of our everyday lives and to cover the man in garments that have been specifically appointed for use in the Lord's house and in the Lord's service.
All of this, of course, serves to bring us into the holiness of the true Temple of God, which is none other than the Lamb of God who takes away the sin of the world.