How Do We Know It Was A Sin Offering?

Q

I’m reading your response regarding Cain and Abel’s offering on your site. You mentioned that no matter whether Cain would have brought the best of his produce or not his offering was not going to be acceptable to God because sin offering required the shedding of innocent blood. I want to know where in Genesis 4 does it tell that they were doing a SIN offering? Secondly, how do we know that the lamb that Abel offered was without blemish?

A

We know it was a sin offering because God warned Cain that if he didn’t present the correct offering sin was crouching at his door and desired to have him (Genesis 4:7). A proper offering would have kept sin at bay. And we know Abel’s offering was without blemish because God accepted it. In Malachi 1:7-8 He condemned the Israelites for offering blemished animals.