Bible Verses About Sacrifices: Were accepted when offered in sincerity and faith

Abel also offered of the firstlings of his flock, and of their fat: and the Lord had respect to Abel, and to his offerings.

And the Lord smelled a sweet savour, and said: I will no more curse the earth for the sake of man: for the imagination and thought of man's heart are prone to evil from his youth: therefore I will no more destroy every living soul as I have done.

By faith Abel offered to God a sacrifice exceeding that of Cain, by which he obtained a testimony that he was just, God giving testimony to his gifts. And by it he being dead yet speaketh.