By faith Abel offered to God a more excellent sacrifice than Cain, through which he obtained witness that he was righteous, God testifying of his gifts; and through it he being dead still speaks. Heb:11.4

Abel - we don't often think of him - do we?
He was the son of Adam and Eve who had a heart for God and because of that brought his sacrifice out of an outpouring of love and devotion to His God.
Cain just brought what he did out of obligation, it was something he had to do rather than wanted to do.
So God got second best.
Abel's heart pleased the Lord. The expression of this heart was an acceptable sacrifice.
God always wants to engage with us at a heart level not a head level. That's one reason why we need to be transformed by the renewing of our minds.... so that our thought patterns can be molded and stirred by our hearts when our spirits are stirred by God's love. Usually we keep our stirrings so fiercely under control that often even we, ourself are not sure of our real feelings about something.
Sadly Cain killed Abel.
The head would often like to kill the heart!
We are also encouraged to present ourselves as a living sacrifice - our reasonable service.
The last part sounds a bit like Cain doesn't it. But that's not the case. Our sacrificial offering of all that we are is the least we can do in gratitude for eternal life. That's the kind of sacrifice that can only come out of a heart that loves God. Obligation, responsibility and a sense of duty are not strong enough to complete that offering.
Only love can lay your whole self down.
We've thought a lot lately about sacrifice, service, witness and testimony.
Where is yours coming from?
Head or heart?