There is absolutely nothing wrong with contemporary worship
The way that Christians have worshiped has changed throughout time, from using the book of Psalms as a hymnbook to writing vast quantities of worship music, many of which make up the hymnody that we continue to use and add to today. Even different Christian cities in the early church worshipped differently, with those in Jerusalem assimilating the Temple and those in the Gentile world transforming their traditions.
However, it seems as though, in recent times, it is typical for some Lutherans to be critical when churches in our synods appear to “deviate” from the typical hymnody and liturgy that we may be familiar with in our own churches. It has led to the use and overuse of judgy terms such as “high church” and “low church” in order to suggest that there is some sort of inherent superiority to the use of certain practices. Such practices are not rooted in the command of our Lord, but rather in adiaphora (or “indifferent matters”).
Unlike with the Old Testament believers (i.e., the people of Israel), Jesus did not leave us with a massive list of laws and practices to be observed when we worship with each other. Rather, Jesus makes one main promise about worship, and that is, “In fact where two or three have gathered together in my name, there I am among them” (Matthew 18:20). Christ does not heave a massive worship blueprint onto His church. Rather, he has a handful of main commands for us dealing with the proper observance of the Sacraments (Baptism and the Lord’s Supper) and the sharing of His Word.
What makes me particularly picky about this issue is when certain bodies (with their own myriad of problems) attack and provoke other Lutherans (who do not lack orthodox teaching rooted in the Holy Scriptures and the Book of Concord) on matters of worship order. It seems particularly ridiculous that we should play the part of Pharisees so well, in that we often strain out a gnat to swallow a camel.
Now, by no means am I going as far as to say that there is anything wrong with having worship that follows that of what has been used since the time circa the Reformation. That would be equally as foolish. My point here is, rather, that there is nothing wrong with certain churches in the Evangelical Lutheran Synod (ELS) and the Wisconsin Synod (WELS), for example, who adhere to a more “contemporary” form or style of worship by using instruments other than the organ and songs that were not written in the 16th century. We ought not be critical in this regard, for we should be mindful of the weak in faith who are not so strong when approached with legalistic demands.
Let it also be debunked that such worship leads to “the compromise of the Gospel,” for where the Word of God is still taught in purity, there is life and salvation regardless of the organization of the service.
This is most undoubtedly the case in any of the congregations in our fellowship, whether they be “contemporary” or “liturgical” in their worship style and practice. Neither worship method can be considered more or less Biblical, for the Bible itself is silent in these matters, by which we have Christian freedom. For if the service is carried out with the intent to hear God’s Word and to receive His gracious forgiveness with thanksgiving, no restriction can condemn this.
What sickens me is the corruption of comments from individuals that run along the lines of, “I would walk out of a church with a drum set.” For where then is your heart? Truthfully, it lies more in technicalities than in love for the Gospel.
It is the Word of God that saves, and while it is this same Word that has influenced how Christians throughout all time have worshipped, it is also by this standard that I can find no fault when churches in our synods tastefully adopt “contemporary” practices. We are the church of all time, not just the church of the Reformation. Thus, we ought to encourage the expansion of praise among us rather than hinder it.
One intresting thing to consider is why we sing so many hymns from the 1600s. If it was just a time period we wouldn't be singing things from that long ago. The reason we sing that old of hymns is because it goes back to the time when the Lutheran church was the strongest (right after the reformation).
I think the key thing here is what kind of "contemporary worship" we are talking about: is it a liturgical worship with a new setting? Or is it a newly written hymn with strong theological lyrics? Or is it a worship designed to "stir up the soul" and a watered-down version of our theology? Sure, there are people who are too harsh and legalistic to matters of Christian Freedom in the church. However, a blanket statement of calling someone "legalistic" or "judgemental" for their defese of the traditional service doesn't consider the reasons they do this. Oftentimes these people care for their church and the importance of the lutheran theology, just like some of the contemporary movement might see church growth for example. COWO is often rooted in how someone feels, much music has elements of decision theology (although not always), and places an emphasis on you. It also doesn't communicate as rich of a theology as time-tested hymns have. This, in fact, may cause one of the cases you mentioned - people weaker in their faith. This may test the purity of God's Word. I also find it difficult to say that COWO is drawing people to the church. More and more people are drawn to the time-tested traditional worship (which may include a few hymns written in the last few decades), and not the charasmatic-laden feeling-focused contemporary service. And there may be sometimes when the contemporary model could lead to hetrodox or even heridical teachings, which would be adequate cause to say, I'm not going to be a part of this church.