And the LORD said to Moses, "Go down and warn the people, lest they break through to gaze at the LORD, and many of them perish. Also let the priests who come near the LORD consecrate themselves, lest the LORD break out against them." But Moses said to the LORD, "The people cannot come up to Mount Sinai; for You warned us, saying, 'Set bounds around the mountain and consecrate it.' " Then the LORD said to him, "Away! Get down and then come up, you and Aaron with you. But do not let the priests and the people break through to come up to the LORD, lest He break out against them." So Moses went down to the people and spoke to them. Exodus 19:21-25
Many people believe that it doesn’t matter what one believes as long as one is sincere. Not according to the Bible.
Beyond that—contrary to what many who claim to believe in the God of the Bible may think—worshiping the true and living God of the Bible in a manner that is unbefitting has great consequences. Approaching Him on our own terms, in ways that we like but He does not, carries the consequence of death!
First of all, since all people are guilty of this infraction to one degree or another, all deserve to have God to “break out against us”! There is good news, however: the blood of Jesus atones for this sin as well!
That the blood of Jesus atones for sins regarding worship does not make those sins any less sinful. Nor does God’s forgiveness make it OK to continue in sin. Rather, having been forgiven, we ought to want to turn from sin all the more.
Turning from the sin of unbiblical worship means being committed to worshiping God reverently. Reverent is the antithesis of the modern craze of casual. Only those who do not understand what it means that God is HOLY, think it right to approach God casually.
Secondly, God is very deliberate about how He is to be worshipped. Proof of that is the fact that the largest portion of the Old Testament Law is about worship (tabernacle, priests, and sacrifices). So, because God is so particular about worship, even though we are not offering it through priests in a temple, we must stick to what God requires and reject any and everything that smacks of our innovations to make worship novel and entertaining to our tastes. Worship is about singing, praying, preaching the Word, and administering the sacraments. Those who want more, want what God does not want—with consequences for disobedience attached!