Genesis 4:4b-5
The LORD looked with favor on Abel and his offering, but on Cain and his offering he did not look with favor. So Cain was very angry, and his face was downcast.
Hebrews 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.

Look at Genesis 4:4b; look carefully; the Bible makes it clear that God didn't favor the person or just the offering, but that he looked upon the person AND his offering... this is why Abel offered the better offering... HIS act of worship was right... you have to have the right attitude of worship, AND present your best... it's tempting to think worship just involves all your heart... if it did involve all your heart to God, you'd very much feel like you have to give your best...

that's the lesson i learned today... i'll add this to the stuff i'm gonna talk about in worship... later...

a n.y. jewish man has an american son... the son grows up distorted by the american ways and becomes materialistic... so the jewish man decides to send his son to israel for a period of time, in the hopes that he'd become a better man by learning the jewish ways... when the time has passed, the son comes home, and to the delight of the jewish man, he has become a better man. then he tells his father, "dad! it was great! i've learned so much! i've become a christian!"
the man is shocked to hear that his son has become a christian... so he goes next door to his jewish neighbor, also a devout judaist... when he explains the incident, he is shocked when the neighbor replies, "y'kno, the exact same thing happened to me! i sent my son to israel, and returns a christian!"
stunned, the two try to find their rabbi, to explain the incidents in the hopes that he could help them... to their surprise, he ALSO tells them that he sent his son to israel to find that he has returned a christian!
so all of them are kneeling before Yahweh, praying desperately for a solution to their problems, when a ray of light bursts through the clouds, to hear a booming voice say, "I sent my son to israel too" :D(please tell me you got that)