A most basic principle of hermenuetics is the Law/Gospel contrast. The Law/Gospel contrast is primary to Reformed theology and vital to a proper interpretation and application of the Bible. In our day, there is a radical shift in thinking about the Law/Gospel contrast among supposedly "reformed" scholars and teachers. While this radical shift is largely due to a desire to combat antinomianism (lit. anti-lawism), which is rampent in modern evangelicalism, the shift itself is radically antinomian. While desiring to enforce the Law, the modern, so-called "reformed" teachers and scholars have actually lowered it and are destroying it.
By denying the Law/Gospel contrast, the new teaching equates them. Thus if the Law is going to be "good news" or Gospel, it must be do-able. Thus the high standard and terror of the Law is lowered and it is redefined to be requiring something closer to good intentions, rather than actual perfection. Not only does this new, low view of the Law ultimately destroy the Gospel, it necessarily must infect and change worship practice.
What a person believes concerning his salvation will determine how he views worship.
If salvation is by grace alone, through faith alone, in Christ alone, then worship, which is glorying in our redemption, will necessarily be confined to that which God alone has called for. In other words, those who believe that they have not contributed to their salvation, will also not seek to contribute to the worship of God. Worship parallels the Gospel in this regard.
With this introduction, notice how Calvin draws these two issues together as well and shows how the logical outworking of a faulty understanding of the Law necessarily results in a faulty understanding of worship:
"Since men have turned aside from pure and holy obedience to God, they have discovered that good intention was sufficient to approve everything. This was to open the door to all superstitions. It has been the origin of the worship of images, the purchase of masses, the filling of churches with pomp and parade, the running about on pilgrimages, the making of vows by each at his own hand. But the abyss here is so profound that it is enough for us to have touched on some examples. So far is it from being permitted to honour God by human inventions, that there would be no firmness nor certainty, neither bottom nor shore in religion: everything would go to wreck, and Christianity differ in nothing from the idolatries of the heathen."