We get together on Sundays to worship God. He is the point of it all. It is our gift to Him. But it's important to remember that we don't decide what our worship is to look like. He decides what we do in our worship of Him. And that makes sense. When you give a gift the point isn't how you feel in giving it. The point is whether the person you're giving the gift to will enjoy it. God has told us what He enjoys when it comes to worship. So, we look through the Bible - all of it - to see what He has said about the worship that we are to offer to Him.
One of the themes you'll find in the preaching of the prophets was that the covenant people were not worshiping their God as they should have. They were including rituals in their worship that came from the surrounding peoples. It got so bad that God rejected the worship that was being offered to Him. He rejected the worship and the people who were offering that worship.
God has given us principles to guide us in our worship. There is much liberty as long as a church structures its worship according to those principles. As we mature as a church we will make changes in what happens on Sunday morning. That's good. But the changes must be guided by those biblical principles.