Faith Offers a Better Sacrifice
Heb 11:4 By faith Abel offered God a better sacrifice than Cain did. By faith he was commended as a righteous man, when God spoke well of his offerings. And by faith he still speaks, even though he is dead.
We are told, "In the course of time Cain brought some of the fruits of the soil as an offering to the LORD. But Abel brought fat portions from some of the firstborn of his flock. The LORD looked with favor on Abel and his offering but on Cain and his offering he did not look with favor." Gen 4:3-5
Both offered sacrifices to God. Just being religious - being involved in religious ceremonies - does not mean one's faith is commendable. Was it not the religious elite who had Jesus Christ crucified? Here it speaks of Abel offering of the firstborn of his flock, but of Cain it does not say that he offered of the first fruits of his fields.
Faith in God means giving God our best. The first commandment is to put God first. We do not honor God by putting other things before him, like our own desires, our families, career, or the like. We are to give God the first fruits. "Honor the LORD with your wealth, with the firstfruits of all your crops; then your barns will be filled to overflowing, and your vats will brim over with new wine." Pr 3:9,10 "Bring the best of the firstfruits of your soil to the house of the LORD your God." Ex 23:19