The first known human to die. (Genesis 4)
Mentioned in Hebrews 11, he left a legacy of faith. As a shepherd, he gave an offering "some of the firstborn of his flock and their fat portions..." which God approved of. We don't know for sure, but the keyword seems to be "firstborn." It was his first "paycheck." Later, it cost him his life as well because of his brother's jealousy. Abel had faith when it cost him something.
In 2 Samuel 24:24 we see another example of this kind of faith from David, "...I will not sacrifice to the Lord my God burnt offerings which cost me nothing." David had faith when it cost him something.
What is faith costing you?
Romans 12:1 “I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice.”