Cain and Abel both brought sacrifices to God. One of them was well received and the other was not. While we do not know specifically why Cain’s was not regarded by God, we do know that Abel offered his sacrifice by faith and the implication is that Cain did not.
Hebrews 11:4 ESV By faith Abel offered to God a more acceptable sacrifice than Cain, through which he was commended as righteous, God commending him by accepting his gifts. And through his faith, though he died, he still speaks.
When I discuss with some people the nature of a worship service, that is a sacrifice that we bring to God when we assemble on Sunday’s, I will be told in so many words that what is important to them about a worship service is that they “feel good” or “enjoy it”. If that is their criteria for deciding is a particular worship service was good or not, there is a serious danger of crossing over into the sacrifice of Cain.
For a sacrifice to be acceptable to God it must be done by faith. The only way to make a sacrifice by faith is to do it the way God tells us to do it. If we do we want to and what we enjoy are we doing what God has asked of us? The two may not be exclusive but we need to start not by asking the worshiper what they want to do but by asking of God: How may I worship you in a way that pleases you?
Are you worship sacrifices regarded by God or rejected by God?