Many of the "worship wars" today are fueled by, I believe, differing views of the nature of worship itself. Clearly differences over what worship is and the function of various worship elements would lead to significant differences over what kind of music we might use in a worship service, for example, and so I believe that a fundamental step toward resolving these debates is to seek to understand how the Bible itself defines worship.
At its most basic level, worship is drawing near to God in fellowship with him and obedience to him such that he is magnified and glorified.
This idea of drawing near to God in worship permeates the storyline of Scripture. It is what Adam and Eve enjoyed as they walked with God in the cool the day (Gen. 2:8). It is described in Exodus 19:17 when Moses "brought the people out of the camp to meet God" at the foot of Mt. Sinai. He had told Pharaoh to let the people go so that they might worship their God in the wilderness, and this is exactly what they intended to do at Sinai. It is what Psalm 100 commands of the Hebrews in Temple worship when it says, "Come into his presence with singing and into his courts with praise." It is what Isaiah experienced as he entered the heavenly throne room of God and saw him high and lifted up. To draw near to God is to enter his very presence in fellowship and obedience.
Ultimately, this is why God created people. God created the world to put on display the excellencies of his own glory, and he created people therein that they might witness that glory and praise him for it. In Isaiah 43:6–7 God proclaims,
Bring my sons from afar and my daughters from the end of the earth, everyone who is called by my name, whom I created for my glory, whom I formed and made.
Likewise, Paul commands in 1 Corinthians 10:31, "Whether you eat, or drink, or whatever you do, do all for the glory of God."
Worship—magnifying God's worth and glory—is the reason God made us.
Adam and Eve's fall into sin—their disobedience of God's commandments—was essentially failure to magnify the worthiness of God to be their master and bring him glory, and thus it was a failure to worship him acceptably. This broke the communion they enjoyed with God and propelled them out from the sanctuary of his presence. After they sinned, and they heard God walking in the garden, "the man and his wife hid themselves from the presence of the LORD God" (Gen 3:8)—they recognized their unworthiness to walk with him. Their sin created a separation between them and their Creator, and they were forced to leave the sanctuary (Gen 3:23–24), never again able to draw near to the presence of God.
All sin is essentially failure to bring God glory (Rom 3:23)—it is failure to worship him. This failure creates barriers from drawing near to God in worship, and it brings with it severe punishment: eternal separation from the presence of God in hell. Sin prevents us from drawing near to God in worship; it prevents us from doing what we were created to do.
However, worship is possible through a sacrifice, the vicarious, substitutionary atonement of the Son of God. Sacrifices in the Mosaic system pictured this kind of atonement, but they were unable to "make perfect those who draw near" (Heb 10:1).
But this sacrifice can perfect those who draw near. Jesus is fully man, and thus he can stand as our substitute, and he is fully God, and thus he can pay an eternal punishment to an eternal, holy God that no normal man could. And because of the perfection and eternality of this sacrifice, it need not be offered day after day after day to atone for sin; it is offered one time and the complete wrath of God is fully appeased.
This is what God pictured when he slew the animal in the garden and covered Adam and Eve's guilt. This is what was pictured when Moses offered a sacrifice at the foot of Mt. Sinai so that the elders of the people could approach God. This is what was pictured each year in Israel on the Day of Atonement when an animal was sacrificed and the high priest entered the holy place to sprinkle blood on the mercy seat. This is what was pictured when the seraph took a burning coal from the altar and placed it on Isaiah's lips, saying, "your guilt is taken away, and your sin atoned for."
And this is pictured no more beautifully than with what happened at the moment of Christ's death. The gospel accounts of the crucifixion tell us that Jesus cried out with a loud voice and gave up his spirit, and at that exact moment, the veil of the temple was torn in two, as if that veil was the body of the Son of God himself prohibiting entrance into the presence of a holy God, and that access that had been lost by the fall of man is now restored! There is now a new and living way (Heb 10:20) to draw near to God, and that way is his Son.
Thus those who repent of their sin—their failure to worship—and put their faith and trust in the sacrifice of Jesus Christ on their behalf are saved from separation from God and enabled once again to draw near to him in worship.
What should be apparent is that the essence of worship is itself the language of the gospel—a drawing near to God in relationship with him, made impossible because of sin that demands eternal judgment, yet restored through the substitutionary atonement of the God-man for those who place their faith in him. The gospel of Jesus Christ makes worship possible.